[Docs] [txt|pdf] [draft-ietf-ipp-mo...] [Diff1] [Diff2] [Errata]

Updated by: 3380, 3382, 3996, 3995 PROPOSED STANDARD
Errata Exist
Network Working Group                                T. Hastings, Editor
Request for Comments: 2911                                    R. Herriot
Obsoletes: 2566                                        Xerox Corporation
Category: Standards Track                                       R. deBry
                                               Utah Valley State College
                                                             S. Isaacson
                                                            Novell, Inc.
                                                               P. Powell
                                                     Astart Technologies
                                                          September 2000


          Internet Printing Protocol/1.1: Model and Semantics

Status of this Memo

   This document specifies an Internet standards track protocol for the
   Internet community, and requests discussion and suggestions for
   improvements.  Please refer to the current edition of the "Internet
   Official Protocol Standards" (STD 1) for the standardization state
   and status of this protocol.  Distribution of this memo is unlimited.

Copyright Notice

   Copyright (C) The Internet Society (2000).  All Rights Reserved.

Abstract

   This document is one of a set of documents, which together describe
   all aspects of a new Internet Printing Protocol (IPP).  IPP is an
   application level protocol that can be used for distributed printing
   using Internet tools and technologies.  This document describes a
   simplified model consisting of abstract objects, their attributes,
   and their operations that is independent of encoding and transport.
   The model consists of a Printer and a Job object.  A Job optionally
   supports multiple documents.  IPP 1.1 semantics allow end-users and
   operators to query printer capabilities, submit print jobs, inquire
   about the status of print jobs and printers, cancel, hold, release,
   and restart print jobs.  IPP 1.1 semantics allow operators to pause,
   resume, and purge (jobs from) Printer objects.  This document also
   addresses security, internationalization, and directory issues.










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   The full set of IPP documents includes:

     Design Goals for an Internet Printing Protocol [RFC2567]
     Rationale for the Structure and Model and Protocol for the Internet
     Printing Protocol [RFC2568]
     Internet Printing Protocol/1.1: Model and Semantics (this document)
     Internet Printing Protocol/1.1: Encoding and Transport [RFC2910]
     Internet Printing Protocol/1.1: Implementer's Guide [IPP-IIG]
     Mapping between LPD and IPP Protocols [RFC2569]

   The "Design Goals for an Internet Printing Protocol" document takes a
   broad look at distributed printing functionality, and it enumerates
   real-life scenarios that help to clarify the features that need to be
   included in a printing protocol for the Internet.  It identifies
   requirements for three types of users: end users, operators, and
   administrators.  It calls out a subset of end user requirements that
   are satisfied in IPP/1.0.  A few OPTIONAL operator operations have
   been added to IPP/1.1.

   The "Rationale for the Structure and Model and Protocol for the
   Internet Printing Protocol" document describes IPP from a high level
   view, defines a roadmap for the various documents that form the suite
   of IPP specification documents, and gives background and rationale
   for the IETF working group's major decisions.

   The "Internet Printing Protocol/1.1: Encoding and Transport" document
   is a formal mapping of the abstract operations and attributes defined
   in the model document onto HTTP/1.1 [RFC2616].  It defines the
   encoding rules for a new Internet MIME media type called
   "application/ipp".  This document also defines the rules for
   transporting over HTTP a message body whose Content-Type is
   "application/ipp".  This document defines a new scheme named 'ipp'
   for identifying IPP printers and jobs.

   The "Internet Printing Protocol/1.1: Implementer's Guide" document
   gives insight and advice to implementers of IPP clients and IPP
   objects.  It is intended to help them understand IPP/1.1 and some of
   the considerations that may assist them in the design of their client
   and/or IPP object implementations.  For example, a typical order of
   processing requests is given, including error checking.  Motivation
   for some of the specification decisions is also included.

   The "Mapping between LPD and IPP Protocols" document gives some
   advice to implementers of gateways between IPP and LPD (Line Printer
   Daemon) implementations.






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Table of Contents

   1.   Introduction                                                 9
   1.1   Simplified Printing Model                                  10
   2.   IPP Objects                                                 12
   2.1   Printer Object                                             13
   2.2   Job Object                                                 15
   2.3   Object Relationships                                       16
   2.4   Object Identity                                            17
   3.   IPP Operations                                              20
   3.1   Common Semantics                                           21
   3.1.1  Required Parameters                                       21
   3.1.2  Operation IDs and Request IDs                             22
   3.1.3  Attributes                                                22
   3.1.4  Character Set and Natural Language Operation Attribute    24
   3.1.4.1   Request Operation Attributes                           25
   3.1.4.2   Response Operation Attributes                          29
   3.1.5  Operation Targets                                         30
   3.1.6  Operation Response Status Codes and Status Messages       32
   3.1.6.1   "status-code" (type2 enum)                             32
   3.1.6.2   "status-message" (text(255))                           33
   3.1.6.3   "detailed-status-message" (text(MAX))                  33
   3.1.6.4   "document-access-error" (text(MAX))                    34
   3.1.7  Unsupported Attributes                                    34
   3.1.8  Versions                                                  36
   3.1.9  Job Creation Operations                                   38
   3.2   Printer Operations                                         41
   3.2.1  Print-Job Operation                                       41
   3.2.1.1   Print-Job Request                                      41
   3.2.1.2   Print-Job Response                                     46
   3.2.2  Print-URI Operation                                       48
   3.2.3  Validate-Job Operation                                    49
   3.2.4  Create-Job Operation                                      49
   3.2.5  Get-Printer-Attributes Operation                          50
   3.2.5.1   Get-Printer-Attributes Request                         51
   3.2.5.2   Get-Printer-Attributes Response                        53
   3.2.6  Get-Jobs Operation                                        54
   3.2.6.1   Get-Jobs Request                                       54
   3.2.6.2   Get-Jobs Response                                      56
   3.2.7  Pause-Printer Operation                                   57
   3.2.7.1   Pause-Printer Request                                  59
   3.2.7.2   Pause-Printer Response                                 60
   3.2.8  Resume-Printer Operation                                  60
   3.2.9  Purge-Jobs Operation                                      61
   3.3   Job Operations                                             62
   3.3.1  Send-Document Operation                                   62
   3.3.1.1   Send-Document Request                                  64
   3.3.1.2   Send-Document Response                                 65



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   3.3.2  Send-URI Operation                                        66
   3.3.3  Cancel-Job Operation                                      66
   3.3.3.1   Cancel-Job Request                                     67
   3.3.3.2   Cancel-Job Response                                    68
   3.3.4  Get-Job-Attributes Operation                              69
   3.3.4.1   Get-Job-Attributes Request                             69
   3.3.4.2   Get-Job-Attributes Response                            70
   3.3.5  Hold-Job Operation                                        71
   3.3.5.1   Hold-Job Request                                       72
   3.3.5.2   Hold-Job Response                                      73
   3.3.6  Release-Job Operation                                     74
   3.3.7  Restart-Job Operation                                     75
   3.3.7.1   Restart-Job Request                                    76
   3.3.7.2   Restart-Job Response                                   78
   4.   Object Attributes                                           78
   4.1   Attribute Syntaxes                                         78
   4.1.1  'text'                                                    79
   4.1.1.1   'textWithoutLanguage'                                  80
   4.1.1.2   'textWithLanguage'                                     80
   4.1.2  'name'                                                    81
   4.1.2.1   'nameWithoutLanguage'                                  82
   4.1.2.2   'nameWithLanguage'                                     82
   4.1.2.3   Matching 'name' attribute values                       83
   4.1.3  'keyword'                                                 84
   4.1.4  'enum'                                                    85
   4.1.5  'uri'                                                     85
   4.1.6  'uriScheme'                                               86
   4.1.7  'charset'                                                 86
   4.1.8  'naturalLanguage'                                         87
   4.1.9  'mimeMediaType'                                           87
   4.1.9.1 Application/octet-stream -- Auto-Sensing                 88
           the document format
   4.1.10 'octetString'                                             89
   4.1.11 'boolean'                                                 89
   4.1.12 'integer'                                                 89
   4.1.13 'rangeOfInteger'                                          90
   4.1.14 'dateTime'                                                90
   4.1.15 'resolution'                                              90
   4.1.16 '1setOf  X'                                               90
   4.2   Job Template Attributes                                    91
   4.2.1  job-priority (integer(1:100))                             94
   4.2.2  job-hold-until (type3 keyword | name (MAX))               95
   4.2.3  job-sheets (type3 keyword | name(MAX))                    96
   4.2.4  multiple-document-handling (type2 keyword)                96
   4.2.5  copies (integer(1:MAX))                                   98
   4.2.6  finishings (1setOf type2 enum)                            98
   4.2.7  page-ranges (1setOf rangeOfInteger (1:MAX))              101
   4.2.8  sides (type2 keyword)                                    102



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   4.2.9  number-up (integer(1:MAX))                               102
   4.2.10 orientation-requested (type2 enum)                       103
   4.2.11 media (type3 keyword | name(MAX))                        104
   4.2.12 printer-resolution (resolution)                          105
   4.2.13 print-quality (type2 enum)                               105
   4.3   Job Description Attributes                                106
   4.3.1  job-uri (uri)                                            107
   4.3.2  job-id (integer(1:MAX))                                  108
   4.3.3  job-printer-uri (uri)                                    108
   4.3.4  job-more-info (uri)                                      108
   4.3.5  job-name (name(MAX))                                     108
   4.3.6  job-originating-user-name (name(MAX))                    109
   4.3.7  job-state (type1 enum)                                   109
   4.3.7.1   Forwarding Servers                                    112
   4.3.7.2   Partitioning of Job States                            112
   4.3.8  job-state-reasons (1setOf  type2 keyword)                113
   4.3.9  job-state-message (text(MAX))                            118
   4.3.10 job-detailed-status-messages (1setOf text(MAX))          118
   4.3.11 job-document-access-errors (1setOf text(MAX))            118
   4.3.12 number-of-documents (integer(0:MAX))                     119
   4.3.13 output-device-assigned (name(127))                       119
   4.3.14 Event Time Job Description Attributes                    119
   4.3.14.1  time-at-creation (integer(MIN:MAX))                   120
   4.3.14.2  time-at-processing (integer(MIN:MAX))                 120
   4.3.14.3  time-at-completed (integer(MIN:MAX))                  120
   4.3.14.4  job-printer-up-time (integer(1:MAX))                  120
   4.3.14.5  date-time-at-creation (dateTime)                      121
   4.3.14.6  date-time-at-processing (dateTime)                    121
   4.3.14.7  date-time-at-completed (dateTime)                     121
   4.3.15 number-of-intervening-jobs (integer(0:MAX))              121
   4.3.16 job-message-from-operator (text(127))                    121
   4.3.17 Job Size Attributes                                      121
   4.3.17.1  job-k-octets (integer(0:MAX))                         122
   4.3.17.2  job-impressions (integer(0:MAX))                      122
   4.3.17.3  job-media-sheets (integer(0:MAX))                     123
   4.3.18 Job Progress Attributes                                  123
   4.3.18.1  job-k-octets-processed (integer(0:MAX))               123
   4.3.18.2  job-impressions-completed (integer(0:MAX))            123
   4.3.18.3  job-media-sheets-completed (integer(0:MAX))           124
   4.3.19 attributes-charset (charset)                             124
   4.3.20 attributes-natural-language (naturalLanguage)            124
   4.4   Printer Description Attributes                            124
   4.4.1  printer-uri-supported (1setOf uri)                       126
   4.4.2  uri-authentication-supported (1setOf type2 keyword)      127
   4.4.3  uri-security-supported (1setOf type2 keyword)            128
   4.4.4  printer-name (name(127))                                 129
   4.4.5  printer-location (text(127))                             129
   4.4.6  printer-info (text(127))                                 130



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   4.4.7  printer-more-info (uri)                                  130
   4.4.8  printer-driver-installer (uri)                           130
   4.4.9  printer-make-and-model (text(127))                       130
   4.4.10 printer-more-info-manufacturer (uri)                     130
   4.4.11 printer-state (type1 enum)                               131
   4.4.12 printer-state-reasons (1setOf type2 keyword)             131
   4.4.13 printer-state-message (text(MAX))                        134
   4.4.14 ipp-versions-supported (1setOf type2 keyword)            134
   4.4.15 operations-supported (1setOf type2 enum)                 135
   4.4.16 multiple-document-jobs-supported (boolean)               136
   4.4.17 charset-configured (charset)                             136
   4.4.18 charset-supported (1setOf charset)                       137
   4.4.19 natural-language-configured (naturalLanguage)            137
   4.4.20 generated-natural-language-supported
          (1setOf naturalLanguage)                                 137
   4.4.21 document-format-default (mimeMediaType)                  138
   4.4.22 document-format-supported (1setOf mimeMediaType)         138
   4.4.23 printer-is-accepting-jobs (boolean)                      138
   4.4.24 queued-job-count (integer(0:MAX))                        138
   4.4.25 printer-message-from-operator (text(127))                139
   4.4.26 color-supported (boolean)                                139
   4.4.27 reference-uri-schemes-supported (1setOf uriScheme)       139
   4.4.28 pdl-override-supported (type2 keyword)                   139
   4.4.29 printer-up-time (integer(1:MAX))                         140
   4.4.30 printer-current-time (dateTime)                          140
   4.4.31 multiple-operation-time-out (integer(1:MAX))             141
   4.4.32 compression-supported (1setOf type3 keyword)             141
   4.4.33 job-k-octets-supported (rangeOfInteger(0:MAX))           142
   4.4.34 job-impressions-supported (rangeOfInteger(0:MAX))        142
   4.4.35 job-media-sheets-supported (rangeOfInteger(0:MAX))       142
   4.4.36 pages-per-minute (integer(0:MAX))                        142
   4.4.37 pages-per-minute-color (integer(0:MAX))                  142
   5.   Conformance                                                143
   5.1   Client Conformance Requirements                           143
   5.2   IPP Object Conformance Requirements                       145
   5.2.1  Objects                                                  145
   5.2.2  Operations                                               145
   5.2.3  IPP Object Attributes                                    146
   5.2.4  Versions                                                 146
   5.2.5  Extensions                                               147
   5.2.6  Attribute Syntaxes                                       147
   5.2.7  Security                                                 148
   5.3   Charset and Natural Language Requirements                 148
   6.   IANA Considerations                                        148
   6.1   Typed 'keyword' and 'enum' Extensions                     149
   6.2   Attribute Extensibility                                   151
   6.3   Attribute Syntax Extensibility                            152
   6.4   Operation Extensibility                                   152



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   6.5   Attribute Group Extensibility                             153
   6.6   Status Code Extensibility                                 153
   6.7   Out-of-band Attribute Value Extensibility                 154
   6.8   Registration of MIME types/sub-types for document-formats 154
   6.9   Registration of charsets for use in 'charset'
         attribute values                                          154
   7.   Internationalization Considerations                        154
   8.   Security Considerations                                    158
   8.1   Security Scenarios                                        159
   8.1.1  Client and Server in the Same Security Domain            159
   8.1.2  Client and Server in Different Security Domains          159
   8.1.3  Print by Reference                                       160
   8.2   URIs in Operation, Job, and Printer attributes            160
   8.3   URIs for each authentication mechanisms                   160
   8.4   Restricted Queries                                        161
   8.5   Operations performed by operators and system
         administrators                                            161
   8.6   Queries on jobs submitted using non-IPP protocols         162
   9.   References                                                 162
   10.  Authors' Addresses                                         166
   11.  Formats for IPP Registration Proposals                     168
   11.1  Type2 keyword attribute values registration               169
   11.2  Type3 keyword attribute values registration               169
   11.3  Type2 enum attribute values registration                  169
   11.4  Type3 enum attribute values registration                  170
   11.5  Attribute registration                                    170
   11.6  Attribute Syntax registration                             171
   11.7  Operation registration                                    171
   11.8  Attribute Group registration                              171
   11.9  Status code registration                                  172
   11.10 Out-of-band Attribute Value registration                  172
   12.  APPENDIX A: Terminology                                    173
   12.1  Conformance Terminology                                   173
   12.1.1 NEED NOT                                                 173
   12.2  Model Terminology                                         173
   12.2.1 Keyword                                                  173
   12.2.2 Attributes                                               173
   12.2.2.1  Attribute Name                                        173
   12.2.2.2  Attribute Group Name                                  174
   12.2.2.3  Attribute Value                                       174
   12.2.2.4  Attribute Syntax                                      174
   12.2.3 Supports                                                 174
   12.2.4 print-stream page                                        176
   12.2.5 impression                                               177
   13. APPENDIX B: Status Codes and Suggested Status Code Messages 177
   13.1  Status Codes                                              178
   13.1.1 Informational                                            178
   13.1.2 Successful Status Codes                                  178



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   13.1.2.1  successful-ok (0x0000)                                178
   13.1.2.2  successful-ok-ignored-or-substituted-attributes
             (0x0001)                                              179
   13.1.2.3  successful-ok-conflicting-attributes (0x0002)         179
   13.1.3 Redirection Status Codes                                 179
   13.1.4 Client Error Status Codes                                179
   13.1.4.1  client-error-bad-request (0x0400)                     180
   13.1.4.2  client-error-forbidden (0x0401)                       180
   13.1.4.3  client-error-not-authenticated (0x0402)               180
   13.1.4.4  client-error-not-authorized (0x0403)                  180
   13.1.4.5  client-error-not-possible (0x0404)                    180
   13.1.4.6  client-error-timeout (0x0405)                         181
   13.1.4.7  client-error-not-found (0x0406)                       181
   13.1.4.8  client-error-gone (0x0407)                            181
   13.1.4.9  client-error-request-entity-too-large (0x0408)        182
   13.1.4.10 client-error-request-value-too-long (0x0409)          182
   13.1.4.11 client-error-document-format-not-supported (0x040A)   182
   13.1.4.12 client-error-attributes-or-values-not-supported
             (0x040B)                                              183
   13.1.4.13 client-error-uri-scheme-not-supported (0x040C)        183
   13.1.4.14 client-error-charset-not-supported (0x040D)           183
   13.1.4.15 client-error-conflicting-attributes (0x040E)          183
   13.1.4.16 client-error-compression-not-supported (0x040F)       184
   13.1.4.17 client-error-compression-error (0x0410)               184
   13.1.4.18 client-error-document-format-error (0x0411)           184
   13.1.4.19 client-error-document-access-error (0x0412)           184
   13.1.5    Server Error Status Codes                             185
   13.1.5.1  server-error-internal-error (0x0500)                  185
   13.1.5.2  server-error-operation-not-supported (0x0501)         185
   13.1.5.3  server-error-service-unavailable (0x0502)             185
   13.1.5.4  server-error-version-not-supported (0x0503)           185
   13.1.5.5  server-error-device-error (0x0504)                    186
   13.1.5.6  server-error-temporary-error (0x0505)                 186
   13.1.5.7  server-error-not-accepting-jobs (0x0506)              187
   13.1.5.8  server-error-busy (0x0507)                            187
   13.1.5.9  server-error-job-canceled (0x0508)                    187
   13.1.5.10 server-error-multiple-document-jobs-not-supported
             (0x0509)                                              187
   13.2  Status Codes for IPP Operations                           187
   14.  APPENDIX C:  "media" keyword values                        190
   15.  APPENDIX D: Processing IPP Attributes                      208
   15.1  Fidelity                                                  209
   15.2  Page Description Language (PDL) Override                  210
   15.3  Using Job Template Attributes During Document Processing  212
   16.  APPENDIX E: Generic Directory Schema                       214
   17.  APPENDIX F:  Differences between the IPP/1.0 and IPP/1.1
        "Model and Semantics" Documents                            215
   18.  Full Copyright Statement                                   224



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1. Introduction

   The Internet Printing Protocol (IPP) is an application level protocol
   that can be used for distributed printing using Internet tools and
   technologies.  IPP version 1.1 (IPP/1.1) focuses primarily on end
   user functionality with a few administrative operations included.
   This document is just one of a suite of documents that fully define
   IPP.  The full set of IPP documents includes:

     Design Goals for an Internet Printing Protocol [RFC2567]
     Rationale for the Structure and Model and Protocol for the Internet
     Printing Protocol [RFC2568]
     Internet Printing Protocol/1.1: Model and Semantics (this document)
     Internet Printing Protocol/1.1: Encoding and Transport [RFC2910]
     Internet Printing Protocol/1.1: Implementer's Guide [IPP-IIG]
     Mapping between LPD and IPP Protocols [RFC2569]

   Anyone reading these documents for the first time is strongly
   encouraged to read the IPP documents in the above order.

   This document is laid out as follows:

   - The rest of Section 1 is an introduction to the IPP simplified
     model for distributed printing.
   - Section 2 introduces the object types covered in the model with
     their basic behaviors, attributes, and interactions.
   - Section 3 defines the operations included in IPP/1.1.  IPP
     operations are synchronous, therefore, for each operation, there is
     a both request and a response.
   - Section 4 defines the attributes (and their syntaxes) that are used
     in the model.
   - Sections 5 - 6 summarizes the implementation conformance
     requirements for objects that support the protocol and IANA
     considerations, respectively.
   - Sections 7 - 11 cover the Internationalization and Security
     considerations as well as References, Author contact information,
     and Formats for Registration Proposals.
   - Sections 12 - 14 are appendices that cover Terminology, Status
     Codes and Messages, and "media" keyword values.

       Note: This document uses terms such as "attributes", "keywords",
       and "support".  These terms have special meaning and are defined
       in the model terminology section 12.2.  Capitalized terms, such
       as MUST, MUST NOT, REQUIRED, SHOULD, SHOULD NOT, MAY, NEED NOT,
       and OPTIONAL, have special meaning relating to conformance.
       These terms are defined in section 12.1 on conformance
       terminology, most of which is taken from RFC 2119 [RFC2119].




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   - Section 15 is an appendix that helps to clarify the effects of
     interactions between related attributes and their values.
   - Section 16 is an appendix that enumerates the subset of Printer
     attributes that form a generic directory schema.  These attributes
     are useful when registering a Printer so that a client can find the
     Printer not just by name, but by filtered searches as well.
   - Section 17 is an appendix summarizing the additions and changes
     from the IPP/1.0 "Model and Semantics" document [RFC2566] to make
     this IPP/1.1 document.
   - Section 18 is the full copyright notice.

1.1 Simplified Printing Model

   In order to achieve its goal of realizing a workable printing
   protocol for the Internet, the Internet Printing Protocol (IPP) is
   based on a simplified printing model that abstracts the many
   components of real world printing solutions.  The Internet is a
   distributed computing environment where requesters of print services
   (clients, applications, printer drivers, etc.) cooperate and interact
   with print service providers.  This model and semantics document
   describes a simple, abstract model for IPP even though the underlying
   configurations may be complex "n-tier" client/server systems.  An
   important simplifying step in the IPP model is to expose only the key
   objects and interfaces required for printing.  The model described in
   this model document does not include features, interfaces, and
   relationships that are beyond the scope of the first version of IPP
   (IPP/1.1).  IPP/1.1 incorporates many of the relevant ideas and
   lessons learned from other specification and development efforts
   [HTPP] [ISO10175] [LDPA] [P1387.4] [PSIS] [RFC1179] [SWP].  IPP is
   heavily influenced by the printing model introduced in the Document
   Printing Application (DPA) [ISO10175] standard.  Although DPA
   specifies both end user and administrative features, IPP version 1.1
   (IPP/1.1) focuses primarily on end user functionality with a few
   additional OPTIONAL operator operations.

   The IPP/1.1 model encapsulates the important components of
   distributed printing into two object types:

      - Printer (Section 2.1)
      - Job (Section 2.2)

   Each object type has an associated set of operations (see section 3)
   and attributes (see section 4).








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   It is important, however, to understand that in real system
   implementations (which lie underneath the abstracted IPP/1.1 model),
   there are other components of a print service which are not
   explicitly defined in the IPP/1.1 model. The following figure
   illustrates where IPP/1.1 fits with respect to these other
   components.

                                +--------------+
                                |  Application |
                      o         +. . . . . . . |
                     \|/        |   Spooler    |
                     / \        +. . . . . . . |   +---------+
                   End-User     | Print Driver |---|  File   |
         +-----------+ +-----+  +------+-------+   +----+----+
         |  Browser  | | GUI |         |                |
         +-----+-----+ +--+--+         |                |
               |          |            |                |
               |      +---+------------+---+            |
   N   D   S   |      |      IPP Client    |------------+
   O   I   E   |      +---------+----------+
   T   R   C   |                |
   I   E   U   |
   F   C   R   -------------- Transport ------------------
   I   T   I
   C   O   T                    |         --+
   A   R   Y           +--------+--------+  |
   T   Y               |    IPP Server   |  |
   I                   +--------+--------+  |
   O                            |           |
   N                   +-----------------+  | IPP Printer
                       |  Print Service  |  |
                       +-----------------+  |
                                |         --+
                       +-----------------+
                       | Output Device(s)|
                       +-----------------+

   An IPP Printer object encapsulates the functions normally associated
   with physical output devices along with the spooling, scheduling and
   multiple device management functions often associated with a print
   server. Printer objects are optionally registered as entries in a
   directory where end users find and select them based on some sort of
   filtered and context based searching mechanism (see section 16).  The
   directory is used to store relatively static information about the
   Printer, allowing end users to search for and find Printers that
   match their search criteria, for example: name, context, printer
   capabilities, etc.  The more dynamic information, such as state,
   currently loaded and ready media, number of jobs at the Printer,



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   errors, warnings, and so forth, is directly associated with the
   Printer object itself rather than with the entry in the directory
   which only represents the Printer object.

   IPP clients implement the IPP protocol on the client side and give
   end users (or programs running on behalf of end users) the ability to
   query Printer objects and submit and manage print jobs.  An IPP
   server is just that part of the Printer object that implements the
   server-side protocol.  The rest of the Printer object implements (or
   gateways into) the application semantics of the print service itself.
   The Printer objects may be embedded in an output device or may be
   implemented on a host on the network that communicates with an output
   device.

   When a job is submitted to the Printer object and the Printer object
   validates the attributes in the submission request, the Printer
   object creates a new Job object.  The end user then interacts with
   this new Job object to query its status and monitor the progress of
   the job.  An end user can also cancel their print jobs by using the
   Job object's Cancel-Job operation.  An end-user can also hold,
   release, and restart their print jobs using the Job object's OPTIONAL
   Hold-Job, Release-Job, and Restart-Job operations, if implemented.

   A privileged operator or administrator of a Printer object can
   cancel, hold, release, and restart any user's job using the REQUIRED
   Cancel-Job and the OPTIONAL Hold-Job, Release-Job, and Restart-Job
   operations.  In additional privileged operator or administrator of a
   Printer object can pause, resume, or purge (jobs from) a Printer
   object using the OPTIONAL Pause-Printer, Resume-Printer, and Purge-
   Jobs operations, if implemented.

   The notification service is out of scope for this IPP/1.1 document,
   but using such a notification service, the end user is able to
   register for and receive Printer specific and Job specific events.
   An end user can query the status of Printer objects and can follow
   the progress of Job objects by polling using the Get-Printer-
   Attributes, Get-Jobs, and Get-Job-Attributes operations.

2. IPP Objects

   The IPP/1.1 model introduces objects of type Printer and Job.  Each
   type of object models relevant aspects of a real-world entity such as
   a real printer or real print job.  Each object type is defined as a
   set of possible attributes that may be supported by instances of that
   object type.  For each object (instance), the actual set of supported
   attributes and values describe a specific implementation.  The
   object's attributes and values describe its state, capabilities,
   realizable features, job processing functions, and default behaviors



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   and characteristics.  For example, the Printer object type is defined
   as a set of attributes that each Printer object potentially supports.
   In the same manner, the Job object type is defined as a set of
   attributes that are potentially supported by each Job object.

   Each attribute included in the set of attributes defining an object
   type is labeled as:

   - "REQUIRED": each object MUST support the attribute.
   - "RECOMMENDED": each object SHOULD support the attribute.
   - "OPTIONAL": each object MAY support the attribute.

   Some definitions of attribute values indicate that an object MUST or
   SHOULD support the value; otherwise, support of the value is
   OPTIONAL.

   However, if an implementation supports an attribute, it MUST support
   at least one of the possible values for that attribute.

2.1 Printer Object

   The major component of the IPP/1.1 model is the Printer object.  A
   Printer object implements the server-side of the IPP/1.1 protocol.
   Using the protocol, end users may query the attributes of the Printer
   object and submit print jobs to the Printer object.  The actual
   implementation components behind the Printer abstraction may take on
   different forms and different configurations.  However, the model
   abstraction allows the details of the configuration of real
   components to remain opaque to the end user.  Section 3 describes
   each of the Printer operations in detail.

   The capabilities and state of a Printer object are described by its
   attributes.  Printer attributes are divided into two groups:

   - "job-template" attributes: These attributes describe supported job
     processing capabilities and defaults for the Printer object. (See
     section 4.2)
   - "printer-description" attributes: These attributes describe the
     Printer object's identification, state, location, references to
     other sources of information about the Printer object, etc. (see
     section 4.4)

   Since a Printer object is an abstraction of a generic document output
   device and print service provider, a Printer object could be used to
   represent any real or virtual device with semantics consistent with
   the Printer object, such as a fax device, an imager, or even a CD
   writer.




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   Some examples of configurations supporting a Printer object include:

      1) An output device with no spooling capabilities
      2) An output device with a built-in spooler
      3) A print server supporting IPP with one or more associated
         output devices
         3a) The associated output devices may or may not be capable of
             spooling jobs
         3b) The associated output devices may or may not support IPP

   The following figures show some examples of how Printer objects can
   be realized on top of various distributed printing configurations.
   The embedded case below represents configurations 1 and 2. The hosted
   and fan-out figures below represent configurations 3a and 3b.

   In this document the term "client" refers to a software entity that
   sends IPP operation requests to an IPP Printer object and accepts IPP
   operation responses.  A client MAY be:

      1. contained within software controlled by an end user, e.g.
         activated by the "Print" menu item in an application or

      2. the print server component that sends IPP requests to either an
         output device or another "downstream" print server.

   The term "IPP Printer" is a network entity that accepts IPP operation
   requests and returns IPP operation responses.  As such, an IPP object
   MAY be:

      1. an (embedded) device component that accepts IPP requests and
         controls the device or

      2. a component of a print server that accepts IPP requests (where
         the print server controls one or more networked devices using
         IPP or other protocols).

   Legend:

   ##### indicates a Printer object which is
         either embedded in an output device or is
         hosted in a server.  The Printer object
         might or might not be capable of queuing/spooling.

   any   indicates any network protocol or direct
         connect, including IPP






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   embedded printer:
                                             output device
                                           +---------------+
    O   +--------+                         |  ###########  |
   /|\  | client |------------IPP------------># Printer #  |
   / \  +--------+                         |  # Object  #  |
                                           |  ###########  |
                                           +---------------+

   hosted printer:
                                           +---------------+
    O   +--------+        ###########      |               |
   /|\  | client |--IPP--># Printer #-any->| output device |
   / \  +--------+        # Object  #      |               |
                          ###########      +---------------+


                                            +---------------+
   fan out:                                 |               |
                                        +-->| output device |
                                    any/    |               |
    O   +--------+      ###########   /     +---------------+
   /|\  | client |-IPP-># Printer #--*
   / \  +--------+      # Object  #   \     +---------------+
                        ########### any\    |               |
                                        +-->| output device |
                                            |               |
                                            +---------------+

2.2 Job Object

   A Job object is used to model a print job.  A Job object contains
   documents.  The information required to create a Job object is sent
   in a create request from the end user via an IPP Client to the
   Printer object.  The Printer object validates the create request, and
   if the Printer object accepts the request, the Printer object creates
   the new Job object.  Section 3 describes each of the Job operations
   in detail.

   The characteristics and state of a Job object are described by its
   attributes.  Job attributes are grouped into two groups as follows:

      - "job-template" attributes: These attributes can be supplied by
        the client or end user and include job processing instructions
        which are intended to override any Printer object defaults
        and/or instructions embedded within the document data. (See
        section 4.2)




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      - "job-description" attributes: These attributes describe the Job
        object's identification, state, size, etc. The client supplies
        some of these attributes, and the Printer object generates
        others. (See section 4.3)

   An implementation MUST support at least one document per Job object.
   An implementation MAY support multiple documents per Job object.  A
   document is either:

      - a stream of document data in a format supported by the Printer
        object (typically a Page Description Language - PDL), or
      - a reference to such a stream of document data

   In IPP/1.1, a document is not modeled as an IPP object, therefore it
   has no object identifier or associated attributes.  All job
   processing instructions are modeled as Job object attributes.  These
   attributes are called Job Template attributes and they apply equally
   to all documents within a Job object.

2.3 Object Relationships

   IPP objects have relationships that are maintained persistently along
   with the persistent storage of the object attributes.

   A Printer object can represent either one or more physical output
   devices or a logical device which "processes" jobs but never actually
   uses a physical output device to put marks on paper.  Examples of
   logical devices include a Web page publisher or a gateway into an
   online document archive or repository.  A Printer object contains
   zero or more Job objects.

   A Job object is contained by exactly one Printer object, however the
   identical document data associated with a Job object could be sent to
   either the same or a different Printer object.  In this case, a
   second Job object would be created which would be almost identical to
   the first Job object, however it would have new (different) Job
   object identifiers (see section 2.4).

   A Job object is either empty (before any documents have been added)
   or contains one or more documents.  If the contained document is a
   stream of document data, that stream can be contained in only one
   document.  However, there can be identical copies of the stream in
   other documents in the same or different Job objects.  If the
   contained document is just a reference to a stream of document data,
   other documents (in the same or different Job object(s)) may contain
   the same reference.





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2.4 Object Identity

   All Printer and Job objects are identified by a Uniform Resource
   Identifier (URI) [RFC2396] so that they can be persistently and
   unambiguously referenced.  Since every URL is a specialized form of a
   URI, even though the more generic term URI is used throughout the
   rest of this document, its usage is intended to cover the more
   specific notion of URL as well.

   An administrator configures Printer objects to either support or not
   support authentication and/or message privacy using Transport Layer
   Security (TLS) [RFC2246] (the mechanism for security configuration is
   outside the scope of this IPP/1.1 document).  In some situations,
   both types of connections (both authenticated and unauthenticated)
   can be established using a single communication channel that has some
   sort of negotiation mechanism.  In other situations, multiple
   communication channels are used, one for each type of security
   configuration.  Section 8 provides a full description of all security
   considerations and configurations.

   If a Printer object supports more than one communication channel,
   some or all of those channels might support and/or require different
   security mechanisms.  In such cases, an administrator could expose
   the simultaneous support for these multiple communication channels as
   multiple URIs for a single Printer object where each URI represents
   one of the communication channels to the Printer object. To support
   this flexibility, the IPP Printer object type defines a multi-valued
   identification attribute called the "printer-uri-supported"
   attribute.  It MUST contain at least one URI.  It MAY contain more
   than one URI.  That is, every Printer object will have at least one
   URI that identifies at least one communication channel to the Printer
   object, but it may have more than one URI where each URI identifies a
   different communication channel to the Printer object.  The
   "printer-uri-supported" attribute has two companion attributes, the
   "uri-security-supported" attribute and the "uri-authentication-
   supported". Both have the same cardinality as "printer-uri-
   supported".  The purpose of the "uri-security-supported" attribute is
   to indicate the security mechanisms (if any) used for each URI listed
   in "printer-uri-supported". The purpose of the "uri-authentication-
   supported" attribute is to indicate the authentication mechanisms (if
   any) used for each URI listed in "printer-uri-supported".  These
   three attributes are fully described in sections 4.4.1, 4.4.2, and
   4.4.3.

   When a job is submitted to the Printer object via a create request,
   the client supplies only a single Printer object URI.  The client
   supplied Printer object URI MUST be one of the values in the
   "printer-uri-supported" Printer attribute.



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   IPP/1.1 does not specify how the client obtains the client supplied
   URI, but it is RECOMMENDED that a Printer object be registered as an
   entry in a directory service.  End-users and programs can then
   interrogate the directory searching for Printers. Section 16 defines
   a generic schema for Printer object entries in the directory service
   and describes how the entry acts as a bridge to the actual IPP
   Printer object.  The entry in the directory that represents the IPP
   Printer object includes the possibly many URIs for that Printer
   object as values in one its attributes.

   When a client submits a create request to the Printer object, the
   Printer object validates the request and creates a new Job object.
   The Printer object assigns the new Job object a URI which is stored
   in the "job-uri" Job attribute.  This URI is then used by clients as
   the target for subsequent Job operations.  The Printer object
   generates a Job URI based on its configured security policy and the
   URI used by the client in the create request.

   For example, consider a Printer object that supports both a
   communication channel secured by the use of SSL3 (using HTTP over
   SSL3 with an "https" schemed URI) and another open communication
   channel that is not secured with SSL3 (using a simple "http" schemed
   URI).  If a client were to submit a job using the secure URI, the
   Printer object would assign the new Job object a secure URI as well.
   If a client were to submit a job using the open-channel URI, the
   Printer would assign the new Job object an open-channel URI.

   In addition, the Printer object also populates the Job object's
   "job-printer-uri" attribute.  This is a reference back to the Printer
   object that created the Job object.  If a client only has access to a
   Job object's "job-uri" identifier, the client can query the Job's
   "job-printer-uri" attribute in order to determine which Printer
   object created the Job object.  If the Printer object supports more
   than one URI, the Printer object picks the one URI supplied by the
   client when creating the job to build the value for and to populate
   the Job's "job-printer-uri" attribute.

   Allowing Job objects to have URIs allows for flexibility and
   scalability.  For example, in some implementations, the Printer
   object might create Jobs that are processed in the same local
   environment as the Printer object itself.  In this case, the Job URI
   might just be a composition of the Printer's URI and some unique
   component for the Job object, such as the unique 32-bit positive
   integer mentioned later in this paragraph.  In other implementations,
   the Printer object might be a central clearing-house for validating
   all Job object creation requests, but the Job object itself might be
   created in some environment that is remote from the Printer object.
   In this case, the Job object's URI may have no physical-location



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   relationship at all to the Printer object's URI.  Again, the fact
   that Job objects have URIs allows for flexibility and scalability,
   however, many existing printing systems have local models or
   interface constraints that force print jobs to be identified using
   only a 32-bit positive integer rather than an independent URI.  This
   numeric Job ID is only unique within the context of the Printer
   object to which the create request was originally submitted.
   Therefore, in order to allow both types of client access to IPP Job
   objects (either by Job URI or by numeric Job ID), when the Printer
   object successfully processes a create request and creates a new Job
   object, the Printer object MUST generate both a Job URI and a Job ID.
   The Job ID (stored in the "job-id" attribute) only has meaning in the
   context of the Printer object to which the create request was
   originally submitted. This requirement to support both Job URIs and
   Job IDs allows all types of clients to access Printer objects and Job
   objects no matter the local constraints imposed on the client
   implementation.

   In addition to identifiers, Printer objects and Job objects have
   names ("printer-name" and "job-name").  An object name NEED NOT be
   unique across all instances of all objects. A Printer object's name
   is chosen and set by an administrator through some mechanism outside
   the scope of this IPP/1.1 document.  A Job object's name is
   optionally chosen and supplied by the IPP client submitting the job.
   If the client does not supply a Job object name, the Printer object
   generates a name for the new Job object.  In all cases, the name only
   has local meaning.

   To summarize:

      - Each Printer object is identified with one or more URIs.  The
        Printer's "printer-uri-supported" attribute contains the URI(s).
      - The Printer object's "uri-security-supported" attribute
        identifies the communication channel security protocols that may
        or may not have been configured for the various Printer object
        URIs (e.g., 'tls' or 'none').
      - The Printer object's "uri-authentication-supported" attribute
        identifies the authentication mechanisms that may or may not
        have been configured for the various Printer object URIs (e.g.,
        'digest' or 'none').
      - Each Job object is identified with a Job URI.  The Job's "job-
        uri" attribute contains the URI.
      - Each Job object is also identified with Job ID which is a 32-
        bit, positive integer.  The Job's "job-id" attribute contains
        the Job ID.  The Job ID is only unique within the context of the
        Printer object  which created the Job object.





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      - Each Job object has a "job-printer-uri" attribute which contains
        the URI of the Printer object that was used to create the Job
        object.  This attribute is used to determine the Printer object
        that created a Job object when given only the URI for the Job
        object.  This linkage is necessary to determine the languages,
        charsets, and operations which are supported on that Job (the
        basis for such support comes from the creating Printer object).
      - Each Printer object has a name (which is not necessarily
        unique).  The administrator chooses and sets this name through
        some mechanism outside the scope of this IPP/1.1 document.  The
        Printer object's "printer-name" attribute contains the name.
      - Each Job object has a name (which is not necessarily unique).
        The client optionally supplies this name in the create request.
        If the client does not supply this name, the Printer object
        generates a name for the Job object. The Job object's "job-name"
        attribute contains the name.

3. IPP Operations

   IPP objects support operations.  An operation consists of a request
   and a response.  When a client communicates with an IPP object, the
   client issues an operation request to the URI for that object.
   Operation requests and responses have parameters that identify the
   operation.  Operations also have attributes that affect the run-time
   characteristics of the operation (the intended target, localization
   information, etc.).  These operation-specific attributes are called
   operation attributes (as compared to object attributes such as
   Printer object attributes or Job object attributes).  Each request
   carries along with it any operation attributes, object attributes,
   and/or document data required to perform the operation.  Each request
   requires a response from the object.  Each response indicates success
   or failure of the operation with a status code as a response
   parameter.  The response contains any operation attributes, object
   attributes, and/or status messages generated during the execution of
   the operation request.

   This section describes the semantics of the IPP operations, both
   requests and responses, in terms of the parameters, attributes, and
   other data associated with each operation.












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   The IPP/1.1 Printer operations are:

     Print-Job (section 3.2.1)
     Print-URI (section 3.2.2)
     Validate-Job (section 3.2.3)
     Create-Job (section 3.2.4)
     Get-Printer-Attributes (section 3.2.5)
     Get-Jobs (section 3.2.6)
     Pause-Printer (section 3.3.5)
     Resume-Printer (section 3.3.6)
     Purge-Jobs (section 3.3.7)

   The Job operations are:

     Send-Document (section 3.3.1)
     Send-URI (section 3.3.2)
     Cancel-Job (section 3.3.3)
     Get-Job-Attributes (section 3.3.4)
     Hold-Job (section 3.3.5)
     Release-Job (section 3.3.6)
     Restart-Job (section 3.3.7)

   The Send-Document and Send-URI Job operations are used to add a new
   document to an existing multi-document Job object created using the
   Create-Job operation.

3.1 Common Semantics

   All IPP operations require some common parameters and operation
   attributes.  These common elements and their semantic characteristics
   are defined and described in more detail in the following sections.

3.1.1 Required Parameters

   Every operation request contains the following REQUIRED parameters:

      - a "version-number",
      - an "operation-id",
      - a "request-id", and
      - the attributes that are REQUIRED for that type of request.

   Every operation response contains the following REQUIRED parameters:

      - a "version-number",
      - a "status-code",
      - the "request-id" that was supplied in the corresponding request,
        and
      - the attributes that are REQUIRED for that type of response.



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   The "Encoding and Transport" document [RFC2910] defines special rules
   for the encoding of these parameters.  All other operation elements
   are represented using the more generic encoding rules for attributes
   and groups of attributes.

3.1.2 Operation IDs and Request IDs

   Each IPP operation request includes an identifying "operation-id"
   value.  Valid values are defined in the "operations-supported"
   Printer attribute section (see section 4.4.15).  The client specifies
   which operation is being requested by supplying the correct
   "operation-id" value.

   In addition, every invocation of an operation is identified by a
   "request-id" value. For each request, the client chooses the
   "request-id" which MUST be an integer (possibly unique depending on
   client requirements) in the range from 1 to 2**31 - 1 (inclusive).
   This "request-id" allows clients to manage multiple outstanding
   requests. The receiving IPP object copies all 32-bits of the client-
   supplied "request-id" attribute into the response so that the client
   can match the response with the correct outstanding request, even if
   the "request-id" is out of range.  If the request is terminated
   before the complete "request-id" is received, the IPP object rejects
   the request and returns a response with a "request-id" of 0.

   Note: In some cases, the transport protocol underneath IPP might be a
   connection oriented protocol that would make it impossible for a
   client to receive responses in any order other than the order in
   which the corresponding requests were sent.  In such cases, the
   "request-id" attribute would not be essential for correct protocol
   operation.  However, in other mappings, the operation responses can
   come back in any order.  In these cases, the "request-id" would be
   essential.

3.1.3 Attributes

   Operation requests and responses are both composed of groups of
   attributes and/or document data.  The attributes groups are:

      - Operation Attributes: These attributes are passed in the
        operation and affect the IPP object's behavior while processing
        the operation request and may affect other attributes or groups
        of attributes.  Some operation attributes describe the document
        data associated with the print job and are associated with new
        Job objects, however most operation attributes do not persist
        beyond the life of the operation.  The description of each
        operation attribute includes conformance statements indicating
        which operation attributes are REQUIRED and which are OPTIONAL



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        for an IPP object to support and which attributes a client MUST
        supply in a request and an IPP object MUST supply in a response.
      - Job Template Attributes: These attributes affect the processing
        of a job.  A client OPTIONALLY supplies Job Template Attributes
        in a create request, and the receiving object MUST be prepared
        to receive all supported attributes.  The Job object can later
        be queried to find out what Job Template attributes were
        originally requested in the create request, and such attributes
        are returned in the response as Job Object Attributes.  The
        Printer object can be queried about its Job Template attributes
        to find out what type of job processing capabilities are
        supported and/or what the default job processing behaviors are,
        though such attributes are returned in the response as Printer
        Object Attributes.  The "ipp-attribute-fidelity" operation
        attribute affects processing of all client-supplied Job Template
        attributes (see sections 3.2.1.2 and 15 for a full description
        of "ipp-attribute-fidelity" and its relationship to other
        attributes).
      - Job Object Attributes: These attributes are returned in response
        to a query operation directed at a Job object.
      - Printer Object Attributes: These attributes are returned in
        response to a query operation directed at a Printer object.
      - Unsupported Attributes: In a create request, the client supplies
        a set of Operation and Job Template attributes.  If any of these
        attributes or their values is unsupported by the Printer object,
        the Printer object returns the set of unsupported attributes in
        the response.  Sections 3.1.7, 3.2.1.2, and  15 give a full
        description of how Job Template attributes supplied by the
        client in a create request are processed by the Printer object
        and how unsupported attributes are returned to the client.
        Because of extensibility, any IPP object might receive a request
        that contains new or unknown attributes or values for which it
        has no support. In such cases, the IPP object processes what it
        can and returns the unsupported attributes in the response. The
        Unsupported Attribute group is defined for all operation
        responses for returning unsupported attributes that the client
        supplied in the request.

   Later in this section, each operation is formally defined by
   identifying the allowed and expected groups of attributes for each
   request and response.  The model identifies a specific order for each
   group in each request or response, but the attributes within each
   group may be in any order, unless specified otherwise.

   The attributes within a group MUST be unique; if an attribute with
   the same name occurs more than once, the group is mal-formed.
   Clients MUST NOT submit such malformed requests and Printers MUST NOT
   return such malformed responses.  If such a malformed request is



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   submitted to a Printer, the Printer MUST either (1) reject the
   request with the 'client-error-bad-request' status code (see section
   13.1.4.1) or (2) process the request normally after selecting only
   one of the attribute instances, depending on implementation.  Which
   attribute is selected when there are duplicate attributes depends on
   implementation.  The IPP Printer MUST NOT use the values from more
   than one such duplicate attribute instance.

   Each attribute definition includes the attribute's name followed by
   the name of its attribute syntax(es) in parenthesizes.  In addition,
   each 'integer' attribute is followed by the allowed range in
   parentheses, (m:n), for values of that attribute.  Each 'text' or
   'name' attribute is followed by the maximum size in octets in
   parentheses, (size), for values of that attribute. For more details
   on attribute syntax notation, see the descriptions of these
   attributes syntaxes in section 4.1.

   Note: Document data included in the operation is not strictly an
   attribute, but it is treated as a special attribute group for
   ordering purposes.  The only operations that support supplying the
   document data within an operation request are Print-Job and Send-
   Document.  There are no operation responses that include document
   data.

   Some operations are REQUIRED for IPP objects to support; the others
   are OPTIONAL (see section 5.2.2).  Therefore, before using an
   OPTIONAL operation, a client SHOULD first use the REQUIRED Get-
   Printer-Attributes operation to query the Printer's "operations-
   supported" attribute in order to determine which OPTIONAL Printer and
   Job operations are actually supported.  The client SHOULD NOT use an
   OPTIONAL operation that is not supported.  When an IPP object
   receives a request to perform an operation it does not support, it
   returns the 'server-error-operation-not-supported' status code (see
   section 13.1.5.2).  An IPP object is non-conformant if it does not
   support a REQUIRED operation.

3.1.4 Character Set and Natural Language Operation Attributes

   Some Job and Printer attributes have values that are text strings and
   names intended for human understanding rather than machine
   understanding (see the 'text' and 'name' attribute syntax
   descriptions in section 4.1).  The following sections describe two
   special Operation Attributes called "attributes-charset" and
   "attributes-natural-language".  These attributes are always part of
   the Operation Attributes group.  For most attribute groups, the order
   of the attributes within the group is not important.  However, for
   these two attributes within the Operation Attributes group, the order
   is critical.  The "attributes-charset" attribute MUST be the first



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   attribute in the group and the "attributes-natural-language"
   attribute MUST be the second attribute in the group.  In other words,
   these attributes MUST be supplied in every IPP request and response,
   they MUST come first in the group, and MUST come in the specified
   order.  For job creation operations, the IPP Printer implementation
   saves these two attributes with the new Job object as Job Description
   attributes.  For the sake of brevity in this document, these
   operation attribute descriptions are not repeated with every
   operation request and response, but have a reference back to this
   section instead.

3.1.4.1 Request Operation Attributes

   The client MUST supply and the Printer object MUST support the
   following REQUIRED operation attributes in every IPP/1.1 operation
   request:

      "attributes-charset" (charset):
         This operation attribute identifies the charset (coded
         character set and encoding method) used by any 'text' and
         'name' attributes that the client is supplying in this request.
         It also identifies the charset that the Printer object MUST use
         (if supported) for all 'text' and 'name' attributes and status
         messages that the Printer object returns in the response to
         this request. See Sections 4.1.1 and 4.1.2 for the definition
         of the 'text' and 'name' attribute syntaxes.

         All clients and IPP objects MUST support the 'utf-8' charset
         [RFC2279] and MAY support additional charsets provided that
         they are registered with IANA [IANA-CS].  If the Printer object
         does not support the client supplied charset value, the Printer
         object MUST reject the request, set the "attributes-charset" to
         'utf-8' in the response, and return the 'client-error-charset-
         not-supported' status code and any 'text' or 'name' attributes
         using the 'utf-8' charset. The Printer NEED NOT return any
         attributes in the Unsupported Attributes Group (See sections
         3.1.7 and 3.2.1.2).  The Printer object MUST indicate the
         charset(s) supported as the values of the "charset-supported"
         Printer attribute (see Section 4.4.18), so that the client can
         query to determine which charset(s) are supported.

         Note to client implementers: Since IPP objects are only
         required to support the 'utf-8' charset, in order to maximize
         interoperability with multiple IPP object implementations, a
         client may want to supply 'utf-8' in the "attributes-charset"
         operation attribute, even though the client is only passing and
         able to present a simpler charset, such as US-ASCII [ASCII] or
         ISO-8859-1 [ISO8859-1].  Then the client will have to filter



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         out (or charset convert) those characters that are returned in
         the response that it cannot present to its user.  On the other
         hand, if both the client and the IPP objects also support a
         charset in common besides utf-8, the client may want to use
         that charset in order to avoid charset conversion or data loss.

         See the 'charset' attribute syntax description in Section 4.1.7
         for the syntax and semantic interpretation of the values of
         this attribute and for example values.

      "attributes-natural-language" (naturalLanguage):
         This operation attribute identifies the natural language used
         by any 'text' and 'name' attributes that the client is
         supplying in this request.  This attribute also identifies the
         natural language that the Printer object SHOULD use for all
         'text' and 'name' attributes and status messages that the
         Printer object returns in the response to this request.  See
         the 'naturalLanguage' attribute syntax description in section
         4.1.8 for the syntax and semantic interpretation of the values
         of this attribute and for example values.

         There are no REQUIRED natural languages required for the
         Printer object to support.  However, the Printer object's
         "generated-natural-language-supported" attribute identifies the
         natural languages supported by the Printer object and any
         contained Job objects for all text strings generated by the IPP
         object.  A client MAY query this attribute to determine which
         natural language(s) are supported for generated messages.

         For any of the attributes for which the Printer object
         generates text, i.e., for the "job-state-message", "printer-
         state-message", and status messages (see Section 3.1.6), the
         Printer object MUST be able to generate these text strings in
         any of its supported natural languages.  If the client requests
         a natural language that is not supported, the Printer object
         MUST return these generated messages in the Printer's
         configured natural language as specified by the Printer's
         "natural-language-configured" attribute" (see Section 4.4.19).

         For other 'text' and 'name' attributes supplied by the client,
         authentication system, operator, system administrator, or
         manufacturer (i.e., for "job-originating-user-name", "printer-
         name" (name), "printer-location" (text), "printer-info" (text),
         and "printer-make-and-model" (text)), the Printer object is
         only required to support the configured natural language of the






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         Printer identified by the Printer object's "natural-language-
         configured" attribute, though support of additional natural
         languages for these attributes is permitted.

         For any 'text' or 'name' attribute in the request that is in a
         different natural language than the value supplied in the
         "attributes-natural-language" operation attribute, the client
         MUST use the Natural Language Override mechanism (see sections
         4.1.1.2 and 4.1.2.2) for each such attribute value supplied.
         The client MAY use the Natural Language Override mechanism
         redundantly, i.e., use it even when the value is in the same
         natural language as the value supplied in the "attributes-
         natural-language" operation attribute of the request.

         The IPP object MUST accept any natural language and any Natural
         Language Override, whether the IPP object supports that natural
         language or not (and independent of the value of the "ipp-
         attribute-fidelity" Operation attribute).  That is the IPP
         object accepts all client supplied values no matter what the
         values are in the Printer object's "generated-natural-
         language-supported" attribute.  That attribute, "generated-
         natural-language-supported", only applies to generated
         messages, not client supplied messages.  The IPP object MUST
         remember that natural language for all client-supplied
         attributes, and when returning those attributes in response to
         a query, the IPP object MUST indicate that natural language.

         Each value whose attribute syntax type is 'text' or 'name' (see
         sections 4.1.1 and 4.1.2) has an Associated Natural-Language.
         This document does not specify how this association is stored
         in a Printer or Job object.  When such a value is encoded in a
         request or response, the natural language is either implicit or
         explicit:

         - In the implicit case, the value contains only the text/name
           value, and the language is specified by the "attributes-
           natural-language" operation attribute in the request or
           response (see sections 4.1.1.1 textWithoutLanguage and
           4.1.2.1 nameWithoutLanguage).

         - In the explicit case (also known as the Natural-Language
           Override case), the value contains both the language and the
           text/name value (see sections 4.1.1.2 textWithLanguage and
           4.1.2.2 nameWithLanguage).

         For example, the "job-name" attribute MAY be supplied by the
         client in a create request.  The text value for this attribute
         will be in the natural language identified by the "attribute-



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         natural-language" attribute, or if different, as identified by
         the Natural Language Override mechanism.  If supplied, the IPP
         object will use the value of the "job-name" attribute to
         populate the Job object's "job-name" attribute.  Whenever any
         client queries the Job object's "job-name" attribute, the IPP
         object returns the attribute as stored and uses the Natural
         Language Override mechanism to specify the natural language, if
         it is different from that reported in the "attributes-natural-
         language" operation attribute of the response.  The IPP object
         MAY use the Natural Language Override mechanism redundantly,
         i.e., use it even when the value is in the same natural
         language as the value supplied in the "attributes-natural-
         language" operation attribute of the response.

         An IPP object MUST NOT reject a request based on a supplied
         natural language in an "attributes-natural-language" Operation
         attribute or in any attribute that uses the Natural Language
         Override.

   Clients SHOULD NOT supply 'text' or 'name' attributes that use an
   illegal combination of natural language and charset.  For example,
   suppose a Printer object supports charsets 'utf-8', 'iso-8859-1', and
   'iso-8859-7'.  Suppose also, that it supports natural languages 'en'
   (English), 'fr' (French), and 'el' (Greek).  Although the Printer
   object supports the charset 'iso-8859-1' and natural language 'el',
   it probably does not support the combination of Greek text strings
   using the 'iso-8859-1' charset.  The Printer object handles this
   apparent incompatibility differently depending on the context in
   which it occurs:

      - In a create request: If the client supplies a text or name
        attribute (for example, the "job-name" operation attribute) that
        uses an apparently incompatible combination, it is a client
        choice that does not affect the Printer object or its correct
        operation.  Therefore, the Printer object simply accepts the
        client supplied value, stores it with the Job object, and
        responds back with the same combination whenever the client (or
        any client) queries for that attribute.
      - In a query-type operation, like Get-Printer-Attributes: If the
        client requests an apparently incompatible combination, the
        Printer object responds (as described in section 3.1.4.2) using
        the Printer's configured natural language rather than the
        natural language requested by the client.

   In either case, the Printer object does not reject the request
   because of the apparent incompatibility.  The potential incompatible
   combination of charset and natural language can occur either at the
   global operation level or at the Natural Language Override



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   attribute-by-attribute level.  In addition, since the response always
   includes explicit charset and natural language information, there is
   never any question or ambiguity in how the client interprets the
   response.

3.1.4.2 Response Operation Attributes

   The Printer object MUST supply and the client MUST support the
   following REQUIRED operation attributes in every IPP/1.1 operation
   response:

      "attributes-charset" (charset):
         This operation attribute identifies the charset used by any
         'text' and 'name' attributes that the Printer object is
         returning in this response.  The value in this response MUST be
         the same value as the "attributes-charset" operation attribute
         supplied by the client in the request.  If this is not possible
         (i.e., the charset requested is not supported), the request
         would have been rejected.  See "attributes-charset" described
         in Section 3.1.4.1 above.

         If the Printer object supports more than just the 'utf-8'
         charset, the Printer object MUST be able to code convert
         between each of the charsets supported on a highest fidelity
         possible basis in order to return the 'text' and 'name'
         attributes in the charset requested by the client.  However,
         some information loss MAY occur during the charset conversion
         depending on the charsets involved.  For example, the Printer
         object may convert from a UTF-8 'a' to a US-ASCII 'a' (with no
         loss of information), from an ISO Latin 1 CAPITAL LETTER A WITH
         ACUTE ACCENT to US-ASCII 'A' (losing the accent), or from a
         UTF-8 Japanese Kanji character to some ISO Latin 1 error
         character indication such as '?', decimal code equivalent, or
         to the absence of a character, depending on implementation.

         Whether an implementation that supports more than one charset
         stores the data in the charset supplied by the client or code
         converts to one of the other supported charsets, depends on
         implementation.  The strategy should try to minimize loss of
         information during code conversion.  On each response, such an
         implementation converts from its internal charset to that
         requested.

      "attributes-natural-language" (naturalLanguage):
         This operation attribute identifies the natural language used
         by any 'text' and 'name' attributes that the IPP object is
         returning in this response.  Unlike the "attributes-charset"
         operation attribute, the IPP object NEED NOT return the same



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         value as that supplied by the client in the request.  The IPP
         object MAY return the natural language of the Job object or the
         Printer's configured natural language as identified by the
         Printer object's "natural-language-configured" attribute,
         rather than the natural language supplied by the client.  For
         any 'text' or 'name' attribute or status message in the
         response that is in a different natural language than the value
         returned in the "attributes-natural-language" operation
         attribute, the IPP object MUST use the Natural Language
         Override mechanism (see sections 4.1.1.2 and 4.1.2.2) on each
         attribute value returned.  The IPP object MAY use the Natural
         Language Override mechanism redundantly, i.e., use it even when
         the value is in the same natural language as the value supplied
         in the "attributes-natural-language" operation attribute of the
         response.

3.1.5 Operation Targets

   All IPP operations are directed at IPP objects.  For Printer
   operations, the operation is always directed at a Printer object
   using one of its URIs (i.e., one of the values in the Printer
   object's "printer-uri-supported" attribute).  Even if the Printer
   object supports more than one URI, the client supplies only one URI
   as the target of the operation.  The client identifies the target
   object by supplying the correct URI in the "printer-uri (uri)"
   operation attribute.

   For Job operations, the operation is directed at either:

      - The Job object itself using the Job object's URI.  In this case,
        the client identifies the target object by supplying the correct
        URI in the "job-uri (uri)" operation attribute.
      - The Printer object that created the Job object using both the
        Printer objects URI and the Job object's Job ID.  Since the
        Printer object that created the Job object generated the Job ID,
        it MUST be able to correctly associate the client supplied Job
        ID with the correct Job object.  The client supplies the Printer
        object's URI in the "printer-uri (uri)" operation attribute and
        the Job object's Job ID in the "job-id (integer(1:MAX))"
        operation attribute.

   If the operation is directed at the Job object directly using the Job
   object's URI, the client MUST NOT include the redundant "job-id"
   operation attribute.







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   The operation target attributes are REQUIRED operation attributes
   that MUST be included in every operation request.  Like the charset
   and natural language attributes (see section 3.1.4), the operation
   target attributes are specially ordered operation attributes.  In all
   cases, the operation target attributes immediately follow the
   "attributes-charset" and "attributes-natural-language" attributes
   within the operation attribute group, however the specific ordering
   rules are:

      - In the case where there is only one operation target attribute
        (i.e., either only the "printer-uri" attribute or only the
        "job-uri" attribute), that attribute MUST be the third attribute
        in the operation attributes group.
      - In the case where Job operations use two operation target
        attributes (i.e., the "printer-uri" and "job-id" attributes),
        the "printer-uri" attribute MUST be the third attribute and the
        "job-id" attribute MUST be the fourth attribute.

   In all cases, the target URIs contained within the body of IPP
   operation requests and responses must be in absolute format rather
   than relative format (a relative URL identifies a resource with the
   scope of the HTTP server, but does not include scheme, host or port).

   The following rules apply to the use of port numbers in URIs that
   identify IPP objects:

      1. If the URI scheme allows the port number to be explicitly
         included in the URI string, and a port number is specified
         within the URI, then that port number MUST be used by the
         client to contact the IPP object.

      2. If the URI scheme allows the port number to be explicitly
         included in the URI string, and a port number is not specified
         within the URI, then default port number implied by that URI
         scheme MUST be used by the client to contact the IPP object.

      3. If the URI scheme does not allow an explicit port number to be
         specified within the URI, then the default port number implied
         by that URI MUST be used by the client to contact the IPP
         object.

   Note: The IPP "Encoding and Transport document [RFC2910] shows a
   mapping of IPP onto HTTP/1.1 [RFC2616] and defines a new default port
   number for using IPP over HTTP/1.1.







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3.1.6 Operation Response Status Codes and Status Messages

   Every operation response includes a REQUIRED "status-code" parameter
   and an OPTIONAL "status-message" operation attribute, and an OPTIONAL
   "detailed-status-message" operation attribute.  The Print-URI and
   Send-URI response MAY include an OPTIONAL "document-access-error"
   operation attribute.

3.1.6.1 "status-code" (type2 enum)

   The REQUIRED "status-code" parameter provides information on the
   processing of a request.

   The status code is intended for use by automata.  A client
   implementation of IPP SHOULD convert status code values into any
   localized message that has semantic meaning to the end user.

   The "status-code" value is a numeric value that has semantic meaning.
   The "status-code" syntax is similar to a "type2 enum" (see section
   4.1 on "Attribute Syntaxes") except that values can range only from
   0x0000 to 0x7FFF.  Section 13 describes the status codes, assigns the
   numeric values, and suggests a corresponding status message for each
   status code for use by the client when the user's natural language is
   English.

   If the Printer performs an operation with no errors and it encounters
   no problems, it MUST return the status code 'successful-ok' in the
   response.  See section 13.

   If the client supplies unsupported values for the following
   parameters or Operation attributes, the Printer object MUST reject
   the operation, NEED NOT return the unsupported attribute value in the
   Unsupported Attributes group, and MUST return the indicated status
   code:

        Parameter/Attribute                 Status code

        version-number      server-error-version-not-supported
        operation-id        server-error-operation-not-supported
        attributes-charset  client-error-charset-not-supported
        compression         client-error-compression-not-supported
        document-format     client-error-document-format-not-supported
        document-uri        client-error-uri-scheme-not-supported,
                             client-error-document-access-error

   If the client supplies unsupported values for other attributes, or
   unsupported attributes, the Printer returns the status code defined
   in section 3.1.7 on Unsupported Attributes.



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3.1.6.2 "status-message" (text(255))

   The OPTIONAL "status-message" operation attribute provides a short
   textual description of the status of the operation.  The "status-
   message" attribute's syntax is "text(255)", so the maximum length is
   255 octets (see section 4.1.1).  The status message is intended for
   the human end user.  If a response does include a "status-message"
   attribute, an IPP client NEED NOT examine or display the messages,
   however it SHOULD do so in some implementation specific manner.  The
   "status-message" is especially useful for a later version of a
   Printer object to return as supplemental information for the human
   user to accompany a status code that an earlier version of a client
   might not understand.

   If the Printer object supports the "status-message" operation
   attribute, the Printer object MUST be able to generate this message
   in any of the natural languages identified by the Printer object's
   "generated-natural-language-supported" attribute (see the
   "attributes-natural-language" operation attribute specified in
   section 3.1.4.1.  Section 13 suggests the text for the status message
   returned by the Printer for use with the English natural language.

   As described in section 3.1.4.1 for any returned 'text' attribute, if
   there is a choice for generating this message, the Printer object
   uses the natural language indicated by the value of the "attributes-
   natural-language" in the client request if supported, otherwise the
   Printer object uses the value in the Printer object's own "natural-
   language-configured" attribute.

   If the Printer object supports the "status-message" operation
   attribute, it SHOULD use the REQUIRED 'utf-8' charset to return a
   status message for the following error status codes (see section 13):
   'client-error-bad-request', 'client-error-charset-not-supported',
   'server-error-internal-error', 'server-error-operation-not-
   supported', and 'server-error-version-not-supported'.  In this case,
   it MUST set the value of the "attributes-charset" operation attribute
   to 'utf-8' in the error response.

3.1.6.3 "detailed-status-message" (text(MAX))

   The OPTIONAL "detailed-status-message" operation attribute provides
   additional more detailed technical and implementation-specific
   information about the operation.  The "detailed-status-message"
   attribute's syntax is "text(MAX)", so the maximum length is 1023
   octets (see section 4.1.1).    If the Printer objects supports the
   "detailed-status-message" operation attribute, the Printer NEED NOT
   localize the message, since it is intended for use by the system
   administrator or other experienced technical persons.  Localization



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   might obscure the technical meaning of such messages.  Clients MUST
   NOT attempt to parse the value of this attribute.  See the
   "document-access-error" operation attribute (section 3.1.6.4) for
   additional errors that a program can process.

3.1.6.4 "document-access-error" (text(MAX))

   This OPTIONAL operation attribute provides additional information
   about any document access errors encountered by the Printer before it
   returned a response to the Print-URI (section 3.2.2) or Send-URI
   (section 3.3.1) operation.  For errors in the protocol identified by
   the URI scheme in the "document-uri" operation attribute, such as
   'http:' or 'ftp:', the error code is returned in parentheses,
   followed by the URI.  For example:

      (404) http://ftp.pwg.org/pub/pwg/ipp/new_MOD/ipp-model-v11.pdf

   Most Internet protocols use decimal error codes (unlike IPP), so the
   ASCII error code representation is in decimal.

3.1.7 Unsupported Attributes

   The Unsupported Attributes group contains attributes that are not
   supported by the operation. This group is primarily for the job
   creation operations, but all operations can return this group.

   A Printer object MUST include an Unsupported Attributes group in a
   response if the status code is one of the following:  'successful-
   ok-ignored-or-substituted-attributes', 'successful-ok-conflicting-
   attributes', 'client-error-attributes-or-values-not-supported' or
   'client-error-conflicting-attributes'.

   If the status code is one of the four specified in the preceding
   paragraph, the Unsupported Attributes group MUST contain all of those
   attributes and only those attributes that are:

      a. an Operation or Job Template attribute supplied in the request,
         and

      b. unsupported by the printer. See below for details on the three
         categories "unsupported" attributes.

   If the status code is one of those in the table in section 3.1.6.1,
   the Unsupported Attributes group NEED NOT contain the unsupported
   parameter or attribute indicated in that table.






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   If the Printer object is not returning any Unsupported Attributes in
   the response, the Printer object SHOULD omit Group 2 rather than
   sending an empty group.  However, a client MUST be able to accept an
   empty group.

   Unsupported attributes fall into three categories:

      1. The Printer object does not support the supplied attribute (no
         matter what the attribute syntax or value).

      2. The Printer object does support the attribute, but does not
         support some or all of the particular attribute syntaxes or
         values supplied by the client (i.e., the Printer object does
         not have those attribute syntaxes or values in its
         corresponding "xxx-supported" attribute).

      3. The Printer object does support the attributes and values
         supplied, but the particular values are in conflict with one
         another, because they violate a constraint, such as not being
         able to staple transparencies.

   In the case of an unsupported attribute name, the Printer object
   returns the client-supplied attribute with a substituted value of
   'unsupported'.  This value's syntax type is "out-of-band" and its
   encoding is defined by special rules for "out-of-band" values in the
   "Encoding and Transport" document [RFC2910].   Its value indicates no
   support for the attribute itself (see the beginning of section 4.1).

   In the case of a supported attribute with one or more unsupported
   attribute syntaxes or values, the Printer object simply returns the
   client-supplied attribute with the unsupported attribute syntaxes or
   values as supplied by the client.  This indicates support for the
   attribute, but no support for that particular attribute syntax or
   value.  If the client supplies a multi-valued attribute with more
   than one value and the Printer object supports the attribute but only
   supports a subset of the client-supplied attribute syntaxes or
   values, the Printer object

   MUST return only those attribute syntaxes or values that are
   unsupported.

   In the case of two (or more) supported attribute values that are in
   conflict with one another (although each is supported independently,
   the values conflict when requested together within the same job), the
   Printer object MUST return all the values that it ignores or
   substitutes to resolve the conflict, but not any of the values that





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   it is still using.  The choice for exactly how to resolve the
   conflict is implementation dependent.  See sections 3.2.1.2 and 15.
   See The Implementer's Guide [IPP-IIG] for an example.

3.1.8 Versions

   Each operation request and response carries with it a "version-
   number" parameter.  Each value of the "version-number" is in the form
   "X.Y" where X is the major version number and Y is the minor version
   number.  By including a version number in the client request, it
   allows the client  to identify which version of IPP it is interested
   in using, i.e., the version whose conformance requirements the client
   may be depending upon the Printer to meet.

   If the IPP object does not support that major version number supplied
   by the client, i.e., the major version field of the "version-number"
   parameter does not match any of the values of the Printer's "ipp-
   versions-supported" (see section 4.4.14), the object MUST respond
   with a status code of 'server-error-version-not-supported' along with
   the closest version number that is supported (see section 13.1.5.4).
   If the major version number is supported, but the minor version
   number is not, the IPP object SHOULD accept and attempt to perform
   the request (or reject the request if the operation is not
   supported), else it rejects the request and returns the 'server-
   error-version-not-supported' status code.  In all cases, the IPP
   object MUST return the "version-number" that it supports that is
   closest to the version number supplied by the client in the request.

   There is no version negotiation per se.  However, if after receiving
   a 'server-error-version-not-supported' status code from an IPP
   object, a client SHOULD try again with a different version number. A
   client MAY also determine the versions supported either from a
   directory that conforms to Appendix E (see section 16) or by querying
   the Printer object's "ipp-versions-supported" attribute (see section
   4.4.14) to determine which versions are supported.

   An IPP object implementation MUST support version '1.1', i.e., meet
   the conformance requirements for IPP/1.1 as specified in this
   document and [RFC2910].  It is recommended that IPP object
   implementations accept any request with the major version '1' (or
   reject the request if the operation is not supported).

   There is only one notion of "version number" that covers both IPP
   Model and IPP Protocol changes. Thus the version number MUST change
   when introducing a new version of the Model and Semantics document
   (this document) or a new version of the "Encoding and Transport"
   document [RFC2910].




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   Changes to the major version number of the Model and Semantics
   document indicate structural or syntactic changes that make it
   impossible for older version of IPP clients and Printer objects to
   correctly parse and correctly process the new or changed attributes,
   operations and responses.  If the major version number changes, the
   minor version numbers is set to zero.  As an example, adding the
   REQUIRED "ipp-attribute-fidelity" attribute to version '1.1' (if it
   had not been part of version '1.0'), would have required a change to
   the major version number, since an IPP/1.0 Printer would not have
   processed a request with the correct semantics that contained the
   "ipp-attribute-fidelity" attribute that it did not know about.  Items
   that might affect the changing of the major version number include
   any changes to the Model and Semantics document (this document) or
   the "Encoding and Transport" document [RFC2910] itself, such as:

      - reordering of ordered attributes or attribute sets
      - changes to the syntax of existing attributes
      - adding REQUIRED (for an IPP object to support) operation
        attribute groups
      - adding values to existing REQUIRED operation attributes
      - adding REQUIRED operations

   Changes to the minor version number indicate the addition of new
   features, attributes and attribute values that may not be understood
   by all IPP objects, but which can be ignored if not understood.
   Items that might affect the changing of the minor version number
   include any changes to the model objects and attributes but not the
   encoding and transport rules [RFC2910] (except adding attribute
   syntaxes).  Examples of such changes are:

      - grouping all extensions not included in a previous version into
        a new version
      - adding new attribute values
      - adding new object attributes
      - adding OPTIONAL (for an IPP object to support) operation
        attributes (i.e., those attributes that an IPP object can ignore
        without confusing clients)
      - adding OPTIONAL (for an IPP object to support) operation
        attribute groups (i.e., those attributes that an IPP object can
        ignore without confusing clients)
      - adding new attribute syntaxes
      - adding OPTIONAL operations
      - changing Job Description attributes or Printer Description
        attributes from OPTIONAL to REQUIRED or vice versa.
      - adding OPTIONAL attribute syntaxes to an existing attribute.

   The encoding of the "version-number" MUST NOT change over any version
   number (either major or minor).  This rule guarantees that all future



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   versions will be backwards compatible with all previous versions (at
   least for checking  the "version-number").  In addition, any protocol
   elements (attributes, error codes, tags, etc.) that are not carried
   forward from one version to the next are deprecated so that they can
   never be reused with new semantics.

   Implementations that support a certain  version NEED NOT support ALL
   previous versions.  As each new  version is defined (through the
   release of a new IPP specification document), that version will
   specify which previous  versions MUST and which versions SHOULD be
   supported in compliant implementations.

3.1.9 Job Creation Operations

   In order to "submit a print job" and create a new Job object, a
   client issues a create request.  A create request is any one of
   following three operation requests:

      - The Print-Job Request: A client that wants to submit a print job
        with only a single document uses the Print-Job operation.  The
        operation allows for the client to "push" the document data to
        the Printer object by including the document data in the request
        itself.

      - The Print-URI Request: A client that wants to submit a print job
        with only a single document (where the Printer object "pulls"
        the document data instead of the client "pushing" the data to
        the Printer object) uses the Print-URI operation.   In this
        case, the client includes in the request only a URI reference to
        the document data (not the document data itself).

      - The Create-Job Request: A client that wants to submit a print
        job with multiple documents uses the Create-Job operation.  This
        operation is followed by an arbitrary number (one or more) of
        Send-Document and/or Send-URI operations (each creating another
        document for the newly create Job object).  The Send-Document
        operation includes the document data in the request (the client
        "pushes" the document data to the printer), and the Send-URI
        operation includes only a URI reference to the document data in
        the request (the Printer "pulls" the document data from the
        referenced location).  The last Send-Document or Send-URI
        request for a given Job object includes a "last-document"
        operation attribute set to 'true' indicating that this is the
        last request.

   Throughout this model document, the term "create request" is used to
   refer to any of these three operation requests.




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   A Create-Job operation followed by only one Send-Document operation
   is semantically equivalent to a Print-Job operation, however, for
   performance reasons, the client SHOULD use the Print-Job operation
   for all single document jobs.  Also, Print-Job is a REQUIRED
   operation (all implementations MUST support it) whereas Create-Job is
   an OPTIONAL operation, hence some implementations might not support
   it.

   Job submission time is the point in time when a client issues a
   create request.  The initial state of every Job object is the
   'pending', 'pending-held', or 'processing' state (see section 4.3.7).
   When the Printer object begins processing the print job, the Job
   object's state moves to 'processing'.  This is known as job
   processing time.  There are validation checks that must be done at
   job submission time and others that must be performed at job
   processing time.

   At job submission time and at the time a Validate-Job operation is
   received, the Printer MUST do the following:

      1. Process the client supplied attributes and either accept or
         reject the request
      2. Validate the syntax of and support for the scheme of any client
         supplied URI

   At job submission time the Printer object MUST validate whether or
   not the supplied attributes, attribute syntaxes, and values are
   supported by matching them with the Printer object's corresponding
   "xxx-supported" attributes.  See section 3.1.7 for details.  [IPP-
   IIG] presents suggested steps for an IPP object to either accept or
   reject any request and additional steps for processing create
   requests.

   At job submission time the Printer object NEED NOT perform the
   validation checks reserved for job processing time such as:

      1. Validating the document data
      2. Validating the actual contents of any client supplied URI
         (resolve the reference and follow the link to the document
         data)

   At job submission time, these additional job processing time
   validation checks are essentially useless, since they require
   actually parsing and interpreting the document data, are not
   guaranteed to be 100% accurate, and MUST be done, yet again, at job
   processing time.  Also, in the case of a URI, checking for
   availability at job submission time does not guarantee availability




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   at job processing time.  In addition, at job processing time, the
   Printer object might discover any of the following conditions that
   were not detectable at job submission time:

      - runtime errors in the document data,
      - nested document data that is in an unsupported format,
      - the URI reference is no longer valid (i.e., the server hosting
        the document might be down), or
      - any other job processing error

   At job submission time, a Printer object, especially a non-spooling
   Printer, MAY accept jobs that it does not have enough space for.  In
   such a situation, a Printer object MAY stop reading data from a
   client for an indefinite period of time.  A client MUST be prepared
   for a write operation to block for an indefinite period of time (see
   section 5.1 on client conformance).

   When a Printer object has too little space for starting a new job, it
   MAY reject a new create request. In this case, a Printer object MUST
   return a response (in reply to the rejected request) with a status-
   code of 'server-error-busy' (see section 14.1.5.8) and it MAY close
   the connection before receiving all bytes of the operation.  A
   Printer SHOULD indicate that it is temporarily unable to accept jobs
   by setting the 'spool-space-full' value in its "printer-state-
   reasons" attribute and removing the value when it can accept another
   job (see section 4.4.12).

   When receiving a 'server-error-busy' status-code in an operation
   response, a client MUST be prepared for the Printer object to close
   the connection before the client has sent all of the data (especially
   for the Print-Job operation). A client MUST be prepared to keep
   submitting a create request until the IPP Printer object accepts the
   create request.

   At job processing time, since the Printer object has already
   responded with a successful status code in the response to the create
   request, if the Printer object detects an error, the Printer object
   is unable to inform the end user of the error with an operation
   status code.   In this case, the Printer, depending on the error, can
   set the job object's "job-state", "job-state-reasons", or "job-
   state-message" attributes to the appropriate value(s) so that later
   queries can report the correct job status.

   Note: Asynchronous notification of events is outside the scope of
   this IPP/1.1 document.






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3.2 Printer Operations

   All Printer operations are directed at Printer objects.  A client
   MUST always supply the "printer-uri" operation attribute in order to
   identify the correct target of the operation.

3.2.1 Print-Job Operation

   This REQUIRED operation allows a client to submit a print job with
   only one document and supply the document data (rather than just a
   reference to the data).  See Section 15 for the suggested steps for
   processing create operations and their Operation and Job Template
   attributes.

3.2.1.1 Print-Job Request

   The following groups of attributes are supplied as part of the
   Print-Job Request:

   Group 1: Operation Attributes

      Natural Language and Character Set:
         The "attributes-charset" and "attributes-natural-language"
         attributes as described in section 3.1.4.1.  The Printer object
         MUST copy these values to the corresponding Job Description
         attributes described in sections 4.3.19 and 4.3.20.

      Target:
         The "printer-uri" (uri) operation attribute which is the target
         for this operation as described in section 3.1.5.

      Requesting User Name:
         The "requesting-user-name" (name(MAX)) attribute SHOULD be
         supplied by the client as described in section 8.3.

      "job-name" (name(MAX)):
         The client OPTIONALLY supplies this attribute.  The Printer
         object MUST support this attribute.  It contains the client
         supplied Job name.  If this attribute is supplied by the
         client, its value is used for the "job-name" attribute of the
         newly created Job object.  The client MAY automatically include
         any information that will help the end-user distinguish amongst
         his/her jobs, such as the name of the application program along
         with information from the document, such as the document name,
         document subject, or source file name.  If this attribute is
         not supplied by the client, the Printer generates a name to use
         in the "job-name" attribute of the newly created Job object
         (see Section 4.3.5).



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      "ipp-attribute-fidelity" (boolean):
         The client OPTIONALLY supplies this attribute.  The Printer
         object MUST support this attribute.  The value 'true' indicates
         that total fidelity to client supplied Job Template attributes
         and values is required, else the Printer object MUST reject the
         Print-Job request.  The value 'false' indicates that a
         reasonable attempt to print the Job object is acceptable and
         the Printer object MUST accept the Print-Job request. If not
         supplied, the Printer object assumes the value is 'false'.  All
         Printer objects MUST support both types of job processing.  See
         section 15 for a full description of "ipp-attribute-fidelity"
         and its relationship to other attributes, especially the
         Printer object's "pdl-override-supported" attribute.

      "document-name" (name(MAX)):
         The client OPTIONALLY supplies this attribute.  The Printer
         object MUST support this attribute.   It contains the client
         supplied document name.  The document name MAY be different
         than the Job name.  Typically, the client software
         automatically supplies the document name on behalf of the end
         user by using a file name or an application generated name.  If
         this attribute is supplied, its value can be used in a manner
         defined by each implementation.  Examples include: printed
         along with the Job (job start sheet, page adornments, etc.),
         used by accounting or resource tracking management tools, or
         even stored along with the document as a document level
         attribute.  IPP/1.1 does not support the concept of document
         level attributes.

      "compression" (type3 keyword):
         The client OPTIONALLY supplies this attribute.  The Printer
         object MUST support this attribute and the "compression-
         supported" attribute (see section 4.4.32).  The client supplied
         "compression" operation attribute identifies the compression
         algorithm used on the document data. The following cases exist:

         a) If the client omits this attribute, the Printer object MUST
            assume that the data is not compressed   (i.e. the Printer
            follows the rules below as if the client supplied the
            "compression" attribute with a value of 'none').
         b) If the client supplies this attribute, but the value is not
            supported by the Printer object, i.e., the value is not one
            of the values of the Printer object's "compression-
            supported" attribute, the Printer object MUST reject the
            request, and return the 'client-error-compression-not-
            supported' status code. See section 3.1.7 for returning
            unsupported attributes and values.




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         c) If the client supplies the attribute and the Printer object
            supports the attribute value, the Printer object uses the
            corresponding decompression algorithm on the document data.
         d) If the decompression algorithm fails before the Printer
            returns an operation response, the Printer object MUST
            reject the request and return the 'client-error-
            compression-error' status code.
         e) If the decompression algorithm fails after the Printer
            returns an operation response, the Printer object MUST abort
            the job and add the 'compression-error' value to the job's
            "job-state-reasons" attribute.
         f) If the decompression algorithm succeeds, the document data
            MUST then have the format specified by the job's "document-
            format" attribute, if supplied (see "document-format"
            operation attribute definition below).

      "document-format" (mimeMediaType):
         The client OPTIONALLY supplies this attribute.  The Printer
         object MUST support this attribute.  The value of this
         attribute identifies the format of the supplied document data.
         The following cases exist:

         a) If the client does not supply this attribute, the Printer
            object assumes that the document data is in the format
            defined by the Printer object's "document-format-default"
            attribute. (i.e. the Printer follows the rules below as if
            the client supplied the "document-format" attribute with a
            value equal to the printer's default value).
         b) If the client supplies this attribute, but the value is not
            supported by the Printer object, i.e., the value is not one
            of the values of the Printer object's "document-format-
            supported" attribute, the Printer object MUST reject the
            request and return the 'client-error-document-format-not-
            supported' status code.
         c) If the client supplies this attribute and its value is
            'application/octet-stream' (i.e. to be auto-sensed, see
            Section 4.1.9.1), and the format is not one of the
            document-formats that the Printer can auto-sense, and this
            check occurs before the Printer returns an operation
            response, then the Printer MUST reject the request and
            return the  'client-error-document-format-not-supported'
            status code.
         d) If the client supplies this attribute, and the value is
            supported by the Printer object, the Printer is capable of
            interpreting the document data.






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         e) If interpreting of the document data fails before the
            Printer returns an operation response, the Printer object
            MUST reject the request and return the 'client-error-
            document-format-error' status code.
         f) If interpreting of the document data fails after the Printer
            returns an operation response, the Printer object MUST abort
            the job and add the 'document-format-error' value to the
            job's "job-state-reasons" attribute.

      "document-natural-language" (naturalLanguage):
         The client OPTIONALLY supplies this attribute.  The Printer
         object OPTIONALLY supports this attribute. This attribute
         specifies the natural language of the document for those
         document-formats that require a specification of the natural
         language in order to image the document unambiguously. There
         are no particular values required for the Printer object to
         support.

      "job-k-octets" (integer(0:MAX)):
         The client OPTIONALLY supplies this attribute.  The Printer
         object OPTIONALLY supports this attribute and the "job-k-
         octets-supported" attribute (see section 4.4.33).  The client
         supplied "job-k-octets" operation attribute identifies the
         total size of the document(s) in K octets being submitted (see
         section 4.3.17.1 for the complete semantics).  If the client
         supplies the attribute and the Printer object supports the
         attribute, the value of the attribute is used to populate the
         Job object's "job-k-octets" Job Description attribute.

         For this attribute and the following two attributes ("job-
         impressions", and "job-media-sheets"), if the client supplies
         the attribute, but the Printer object does not support the
         attribute, the Printer object ignores the client-supplied
         value.  If the client supplies the attribute and the Printer
         supports the attribute, and the value is within the range of
         the corresponding Printer object's "xxx-supported" attribute,
         the Printer object MUST use the value to populate the Job
         object's "xxx" attribute.  If the client supplies the attribute
         and the Printer supports the attribute, but the value is
         outside the range of the corresponding Printer object's "xxx-
         supported" attribute, the Printer object MUST copy the
         attribute and its value to the Unsupported Attributes response
         group, reject the request, and return the 'client-error-
         attributes-or-values-not-supported' status code.  If the client
         does not supply the attribute, the Printer object MAY choose to
         populate the corresponding Job object attribute depending on
         whether the Printer object supports the attribute and is able
         to calculate or discern the correct value.



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      "job-impressions" (integer(0:MAX)):
         The client OPTIONALLY supplies this attribute.  The Printer
         object OPTIONALLY supports this attribute and the "job-
         impressions-supported" attribute (see section 4.4.34).  The
         client supplied "job-impressions" operation attribute
         identifies the total size in number of impressions of the
         document(s) being submitted (see section 4.3.17.2 for the
         complete semantics).

         See last paragraph under "job-k-octets".

      "job-media-sheets" (integer(0:MAX)):
         The client OPTIONALLY supplies this attribute.  The Printer
         object OPTIONALLY supports this attribute and the "job-media-
         sheets-supported" attribute (see section 4.4.35).  The client
         supplied "job-media-sheets" operation attribute identifies the
         total number of media sheets to be produced for this job (see
         section 4.3.17.3 for the complete semantics).

         See last paragraph under "job-k-octets".

   Group 2: Job Template Attributes

      The client OPTIONALLY supplies a set of Job Template attributes as
      defined in section 4.2.  If the client is not supplying any Job
      Template attributes in the request, the client SHOULD omit Group 2
      rather than sending an empty group.  However, a Printer object
      MUST be able to accept an empty group.

   Group 3: Document Content

      The client MUST supply the document data to be processed.

      In addition to the MANDATORY parameters required for every
      operation request, the simplest Print-Job Request consists of just
      the "attributes-charset" and "attributes-natural-language"
      operation attributes; the "printer-uri" target operation
      attribute; the Document Content and nothing else.  In this simple
      case, the Printer object:

      - creates a new Job object (the Job object contains a single
        document),
      - stores a generated Job name in the "job-name" attribute in the
        natural language and charset requested (see Section 3.1.4.1) (if
        those are supported, otherwise using the Printer object's
        default natural language and charset), and





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      - at job processing time, uses its corresponding default value
        attributes for the supported Job Template attributes that were
        not supplied by the client as IPP attribute or embedded
        instructions in the document data.

3.2.1.2 Print-Job Response

   The Printer object MUST return to the client the following sets of
   attributes as part of the Print-Job Response:

   Group 1: Operation Attributes

      Status Message:
         In addition to the REQUIRED status code returned in every
         response, the response OPTIONALLY includes a "status-message"
         (text(255)) and/or a "detailed-status-message" (text(MAX))
         operation attribute as described in sections 13 and 3.1.6.  If
         the client supplies unsupported or conflicting Job Template
         attributes or values, the Printer object MUST reject or accept
         the Print-Job request depending on the whether the client
         supplied a 'true' or 'false' value for the "ipp-attribute-
         fidelity" operation attribute.  See the Implementer's Guide
         [IPP-IIG] for a complete description of the suggested steps for
         processing a create request.

      Natural Language and Character Set:
         The "attributes-charset" and "attributes-natural-language"
         attributes as described in section 3.1.4.2.

   Group 2: Unsupported Attributes

      See section 3.1.7 for details on returning Unsupported Attributes.

      The value of the "ipp-attribute-fidelity" supplied by the client
      does not affect what attributes the Printer object returns in this
      group.  The value of "ipp-attribute-fidelity" only affects whether
      the Print-Job operation is accepted or rejected.  If the job is
      accepted, the client may query the job using the Get-Job-
      Attributes operation requesting the unsupported attributes that
      were returned in the create response to see which attributes were
      ignored (not stored on the Job object) and which attributes were
      stored with other (substituted) values.









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   Group 3: Job Object Attributes

      "job-uri" (uri):
         The Printer object MUST return the Job object's URI by
         returning the contents of the REQUIRED "job-uri" Job object
         attribute.  The client uses the Job object's URI when directing
         operations at the Job object.  The Printer object always uses
         its configured security policy when creating the new URI.
         However, if the Printer object supports more than one URI, the
         Printer object also uses information about which URI was used
         in the Print-Job Request to generated the new URI so that the
         new URI references the correct access channel.  In other words,
         if the Print-Job Request comes in over a secure channel, the
         Printer object MUST generate a Job URI that uses the secure
         channel as well.

      "job-id" (integer(1:MAX)):
         The Printer object MUST return the Job object's Job ID by
         returning the REQUIRED  "job-id" Job object attribute.  The
         client uses this "job-id" attribute in conjunction with the
         "printer-uri" attribute used in the Print-Job Request when
         directing Job operations at the Printer object.

      "job-state" (type1 enum):
         The Printer object MUST return the Job object's REQUIRED "job-
         state" attribute. The value of this attribute (along with the
         value of the next attribute:  "job-state-reasons") is taken
         from a "snapshot" of the new Job object at some meaningful
         point in time (implementation defined) between when the Printer
         object receives the Print-Job Request and when the Printer
         object returns the response.

      "job-state-reasons" (1setOf type2 keyword):
         The Printer object MUST return the Job object's REQUIRED "job-
         state-reasons" attribute.

      "job-state-message" (text(MAX)):
         The Printer object OPTIONALLY returns the Job object's OPTIONAL
         "job-state-message" attribute.  If the Printer object supports
         this attribute then it MUST be returned in the response.  If
         this attribute is not returned in the response, the client can
         assume that the "job-state-message" attribute is not supported
         and will not be returned in a subsequent Job object query.

      "number-of-intervening-jobs" (integer(0:MAX)):
         The Printer object OPTIONALLY returns the Job object's OPTIONAL
         "number-of-intervening-jobs" attribute.  If the Printer object
         supports this attribute then it MUST be returned in the



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         response.  If this attribute is not returned in the response,
         the client can assume that the "number-of-intervening-jobs"
         attribute is not supported and will not be returned in a
         subsequent Job object query.

         Note: Since any printer state information which affects a job's
         state is reflected in the "job-state" and "job-state-reasons"
         attributes, it is sufficient to return only these attributes
         and no specific printer status attributes.

   Note: In addition to the MANDATORY parameters required for every
   operation response, the simplest response consists of the just the
   "attributes-charset" and "attributes-natural-language" operation
   attributes and the "job-uri", "job-id", and "job-state" Job Object
   Attributes.  In this simplest case, the status code is 'successful-
   ok' and there is no "status-message" or "detailed-status-message"
   operation attribute.

3.2.2 Print-URI Operation

   This OPTIONAL operation is identical to the Print-Job operation
   (section 3.2.1) except that a client supplies a URI reference to the
   document data using the "document-uri" (uri) operation attribute (in
   Group 1) rather than including the document data itself.  Before
   returning the response, the Printer MUST validate that the Printer
   supports the retrieval method (e.g., http, ftp, etc.) implied by the
   URI, and MUST check for valid URI syntax.  If the client-supplied URI
   scheme is not supported, i.e. the value is not in the Printer
   object's "referenced-uri-scheme-supported" attribute, the Printer
   object MUST reject the request and return the 'client-error-uri-
   scheme-not-supported' status code.

   The IPP Printer MAY validate the accessibility of the document as
   part of the operation or subsequently.  If the Printer determines an
   accessibility problem before returning an operation response, it
   rejects the request and returns the 'client-error-document-access-
   error' status code.  The Printer MAY also return a specific document
   access error code using the "document-access-error" operation
   attribute (see section 3.1.6.4).

   If the Printer determines this document accessibility problem after
   accepting the request and returning an operation response with one of
   the successful status codes, the Printer adds the 'document-access-
   error' value to the job's "job-state-reasons" attribute and MAY
   populate the job's "job-document-access-errors" Job Description
   attribute (see section 4.3.11).  See The Implementer's Guide [IPP-
   IIG] for suggested additional checks.




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   If the Printer object supports this operation, it MUST support the
   "reference-uri-schemes-supported" Printer attribute (see section
   4.4.27).

   It is up to the IPP object to interpret the URI and subsequently
   "pull" the document from the source referenced by the URI string.

3.2.3 Validate-Job Operation

   This REQUIRED operation is similar to the Print-Job operation
   (section 3.2.1) except that a client supplies no document data and
   the Printer allocates no resources (i.e., it does not create a new
   Job object).  This operation is used only to verify capabilities of a
   printer object against whatever attributes are supplied by the client
   in the Validate-Job request.  By using the Validate-Job operation a
   client can validate that an identical Print-Job operation (with the
   document data) would be accepted. The Validate-Job operation also
   performs the same security negotiation as the Print-Job operation
   (see section 8), so that a client can check that the client and
   Printer object security requirements can be met before performing a
   Print-Job operation.

   The Validate-Job operation does not accept a "document-uri" attribute
   in order to allow a client to check that the same Print-URI operation
   will be accepted, since the client doesn't send the data with the
   Print-URI operation.  The client SHOULD just issue the Print-URI
   request.

   The Printer object returns the same status codes, Operation
   Attributes (Group 1) and Unsupported Attributes (Group 2) as the
   Print-Job operation.  However, no Job Object Attributes (Group 3) are
   returned, since no Job object is created.

3.2.4 Create-Job Operation

   This OPTIONAL operation is similar to the Print-Job operation
   (section 3.2.1) except that in the Create-Job request, a client does
   not supply document data or any reference to document data.  Also,
   the client does not supply any of the "document-name", "document-
   format", "compression", or "document-natural-language" operation
   attributes.  This operation is followed by one or more Send-Document
   or Send-URI operations.  In each of those operation requests, the
   client OPTIONALLY supplies the "document-name", "document-format",
   and "document-natural-language" attributes for each document in the
   multi-document Job object.






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   If a Printer object supports the Create-Job operation, it MUST also
   support the Send-Document operation and also MAY support the Send-URI
   operation.

   If the Printer object supports this operation, it MUST support the
   "multiple-operation-time-out" Printer attribute (see section 4.4.31).

   If the Printer object supports this operation, then it MUST support
   the "multiple-document-jobs-supported" Printer Description attribute
   (see section 4.4.16) and indicate whether or not it supports
   multiple-document jobs.

   If the Printer object supports this operation and supports multiple
   documents in a job, then it MUST support the "multiple-document-
   handling" Job Template job attribute with at least one value (see
   section 4.2.4) and the associated "multiple-document-handling-
   default" and "multiple-document-handling-supported" Job Template
   Printer attributes (see section 4.2).

   After the Create-Job operation has completed, the value of the "job-
   state" attribute is similar to the "job-state" after a Print-Job,
   even though no document-data has arrived.  A Printer MAY set the
   'job-data-insufficient' value of the job's "job-state-reason"
   attribute to indicate that processing cannot begin until sufficient
   data has arrived and set the "job-state" to either 'pending' or
   'pending-held'.  A non-spooling printer that doesn't implement the
   'pending' job state may even set the "job-state" to 'processing',
   even though there is not yet any data to process.  See sections 4.3.7
   and 4.3.8.

3.2.5 Get-Printer-Attributes Operation

   This REQUIRED operation allows a client to request the values of the
   attributes of a Printer object.   In the request, the client supplies
   the set of Printer attribute names and/or attribute group names in
   which the requester is interested.  In the response, the Printer
   object returns a corresponding attribute set with the appropriate
   attribute values filled in.

   For Printer objects, the possible names of attribute groups are:

      - 'job-template': the subset of the Job Template attributes that
        apply to a Printer object (the last two columns of the table in
        Section 4.2) that the implementation supports for Printer
        objects.
      - 'printer-description': the subset of the attributes specified in
        Section 4.4 that the implementation supports for Printer
        objects.



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      - 'all': the special group 'all' that includes all attributes that
        the implementation supports for Printer objects.

   Since a client MAY request specific attributes or named groups, there
   is a potential that there is some overlap.  For example, if a client
   requests, 'printer-name' and 'all', the client is actually requesting
   the "printer-name" attribute twice: once by naming it explicitly, and
   once by inclusion in the 'all' group.  In such cases, the Printer
   object NEED NOT return each attribute only once in the response even
   if it is requested multiple times.  The client SHOULD NOT request the
   same attribute in multiple ways.

   It is NOT REQUIRED that a Printer object support all attributes
   belonging to a group (since some attributes are OPTIONAL).  However,
   it is REQUIRED that each Printer object support all group names.

3.2.5.1 Get-Printer-Attributes Request

   The following sets of attributes are part of the Get-Printer-
   Attributes Request:

   Group 1: Operation Attributes

      Natural Language and Character Set:
         The "attributes-charset" and "attributes-natural-language"
         attributes as described in section 3.1.4.1.

      Target:
         The "printer-uri" (uri) operation attribute which is the target
         for this operation as described in section 3.1.5.

      Requesting User Name:
         The "requesting-user-name" (name(MAX)) attribute SHOULD be
         supplied by the client as described in section 8.3.

      "requested-attributes" (1setOf keyword):
         The client OPTIONALLY supplies a set of attribute names and/or
         attribute group names in whose values the requester is
         interested.  The Printer object MUST support this attribute.
         If the client omits this attribute, the Printer MUST respond as
         if this attribute had been supplied with a value of 'all'.

      "document-format" (mimeMediaType):
         The client OPTIONALLY supplies this attribute.  The Printer
         object MUST support this attribute.  This attribute is useful
         for a Printer object to determine the set of supported
         attribute values that relate to the requested document format.
         The Printer object MUST return the attributes and values that



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         it uses to validate a job on a create or Validate-Job operation
         in which this document format is supplied. The Printer object
         SHOULD return only (1) those attributes that are supported for
         the specified format and (2) the attribute values that are
         supported for the specified document format.  By specifying the
         document format, the client can get the Printer object to
         eliminate the attributes and values that are not supported for
         a specific document format.  For example, a Printer object
         might have multiple interpreters to support both
         'application/postscript' (for PostScript) and 'text/plain' (for
         text) documents.  However, for only one of those interpreters
         might the Printer object be able to support "number-up" with
         values of '1', '2', and '4'.  For the other interpreter it
         might be able to only support "number-up" with a value of '1'.
         Thus a client can use the Get-Printer-Attributes operation to
         obtain the attributes and values that will be used to
         accept/reject a create job operation.

         If the Printer object does not distinguish between different
         sets of supported values for each different document format
         when validating jobs in the create and Validate-Job operations,
         it MUST NOT distinguish between different document formats in
         the Get-Printer-Attributes operation. If the Printer object
         does distinguish between different sets of supported values for
         each different document format specified by the client, this
         specialization applies only to the following Printer object
         attributes:

      - Printer attributes that are Job Template attributes ("xxx-
        default" "xxx-supported", and "xxx-ready" in the Table in
        Section 4.2),
      - "pdl-override-supported",
      - "compression-supported",
      - "job-k-octets-supported",
      - "job-impressions-supported",
      - "job-media-sheets-supported",
      - "printer-driver-installer",
      - "color-supported", and
      - "reference-uri-schemes-supported"

      The values of all other Printer object attributes (including
      "document-format-supported") remain invariant with respect to the
      client supplied document format (except for new Printer
      description attribute as registered according to section 6.2).

      If the client omits this "document-format" operation attribute,
      the Printer object MUST respond as if the attribute had been
      supplied with the value of the Printer object's "document-format-



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      default" attribute.  It is RECOMMENDED that the client always
      supply a value for "document-format", since the Printer object's
      "document-format-default" may be 'application/octet-stream', in
      which case the returned attributes and values are for the union of
      the document formats that the Printer can automatically sense.
      For more details, see the description of the 'mimeMediaType'
      attribute syntax in section 4.1.9.

      If the client supplies a value for the "document-format" Operation
      attribute that is not supported by the Printer, i.e., is not among
      the values of the Printer object's "document-format-supported"
      attribute, the Printer object MUST reject the operation and return
      the 'client-error-document-format-not-supported' status code.

3.2.5.2 Get-Printer-Attributes Response

   The Printer object returns the following sets of attributes as part
   of the Get-Printer-Attributes Response:

   Group 1: Operation Attributes

      Status Message:
        In addition to the REQUIRED status code returned in every
        response, the response OPTIONALLY includes a "status-message"
        (text(255)) and/or a "detailed-status-message" (text(MAX))
        operation attribute as described in sections 13 and  3.1.6.

      Natural Language and Character Set:
        The "attributes-charset" and "attributes-natural-language"
        attributes as described in section 3.1.4.2.

   Group 2: Unsupported Attributes

      See section 3.1.7 for details on returning Unsupported Attributes.

      The response NEED NOT contain the "requested-attributes" operation
      attribute with any supplied values (attribute keywords) that were
      requested by the client but are not supported by the IPP object.
      If the Printer object does return unsupported attributes
      referenced in the "requested-attributes" operation attribute and
      that attribute included group names, such as 'all', the
      unsupported attributes MUST NOT include attributes described in
      the standard but not supported by the implementation.








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   Group 3: Printer Object Attributes

      This is the set of requested attributes and their current values.
      The Printer object ignores (does not respond with) any requested
      attribute which is not supported.  The Printer object MAY respond
      with a subset of the supported attributes and values, depending on
      the security policy in force.  However, the Printer object MUST
      respond with the 'unknown' value for any supported attribute
      (including all REQUIRED attributes) for which the Printer object
      does not know the value.  Also the Printer object MUST respond
      with the 'no-value' for any supported attribute (including all
      REQUIRED attributes) for which the system administrator has not
      configured a value.  See the description of the "out-of-band"
      values in the beginning of Section 4.1.

3.2.6 Get-Jobs Operation

   This REQUIRED operation allows a client to retrieve the list of Job
   objects belonging to the target Printer object.  The client may also
   supply a list of Job attribute names and/or attribute group names.  A
   group of Job object attributes will be returned for each Job object
   that is returned.

   This operation is similar to the Get-Job-Attributes operation, except
   that this Get-Jobs operation returns attributes from possibly more
   than one object.

3.2.6.1 Get-Jobs Request

   The client submits the Get-Jobs request to a Printer object.

   The following groups of attributes are part of the Get-Jobs Request:

   Group 1: Operation Attributes

      Natural Language and Character Set:
         The "attributes-charset" and "attributes-natural-language"
         attributes as described in section 3.1.4.1.

      Target:
         The "printer-uri" (uri) operation attribute which is the target
         for this operation as described in section 3.1.5.

      Requesting User Name:
         The "requesting-user-name" (name(MAX)) attribute SHOULD be
         supplied by the client as described in section 8.3.





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      "limit" (integer(1:MAX)):
         The client OPTIONALLY supplies this attribute.  The Printer
         object MUST support this attribute. It is an integer value that
         determines the maximum number of jobs that a client will
         receive from the Printer even if "which-jobs" or "my-jobs"
         constrain which jobs are returned.  The limit is a "stateless
         limit" in that if the value supplied by the client is 'N', then
         only the first 'N' jobs are returned in the Get-Jobs Response.
         There is no mechanism to allow for the next 'M' jobs after the
         first 'N' jobs.  If the client does not supply this attribute,
         the Printer object responds with all applicable jobs.

      "requested-attributes" (1setOf type2 keyword):
         The client OPTIONALLY supplies this attribute.  The Printer
         object MUST support this attribute.  It is a set of Job
         attribute names and/or attribute groups names in whose values
         the requester is interested.  This set of attributes is
         returned for each Job object that is returned.  The allowed
         attribute group names are the same as those defined in the
         Get-Job-Attributes operation in section 3.3.4.  If the client
         does not supply this attribute, the Printer MUST respond as if
         the client had supplied this attribute with two values: 'job-
         uri' and 'job-id'.

      "which-jobs" (type2 keyword):
         The client OPTIONALLY supplies this attribute.  The Printer
         object MUST support this attribute.  It indicates which Job
         objects MUST be returned by the Printer object. The values for
         this attribute are:

      'completed': This includes any Job object whose state is
         'completed', 'canceled', or 'aborted'.
      'not-completed': This includes any Job object whose state is
         'pending', 'processing', 'processing-stopped', or 'pending-
         held'.

         A Printer object MUST support both values.  However, if the
         implementation does not keep jobs in the 'completed',
         'canceled', and 'aborted' states, then it returns no jobs when
         the 'completed' value is supplied.

         If a client supplies some other value, the Printer object MUST
         copy the attribute and the unsupported value to the Unsupported
         Attributes response group, reject the request, and return the
         'client-error-attributes-or-values-not-supported' status code.






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         If the client does not supply this attribute, the Printer
         object MUST respond as if the client had supplied the attribute
         with a value of 'not-completed'.

      "my-jobs" (boolean):
         The client OPTIONALLY supplies this attribute.  The Printer
         object MUST support this attribute.  It indicates whether jobs
         from all users or just the jobs submitted by the requesting
         user of this request MUST be considered as candidate jobs to be
         returned by the Printer object.  If the client does not supply
         this attribute, the Printer object MUST respond as if the
         client had supplied the attribute with a value of 'false',
         i.e., jobs from all users.  The means for authenticating the
         requesting user and matching the jobs is described in section
         8.

3.2.6.2 Get-Jobs Response

   The Printer object returns all of the Job objects up to the number
   specified by the "limit" attribute that match the criteria as defined
   by the attribute values supplied by the client in the request.  It is
   possible that no Job objects are returned since there may literally
   be no Job objects at the Printer, or there may be no Job objects that
   match the criteria supplied by the client.  If the client requests
   any Job attributes at all, there is a set of Job Object Attributes
   returned for each Job object.

   It is not an error for the Printer to return 0 jobs. If the response
   returns 0 jobs because there are no jobs matching the criteria, and
   the request would have returned 1 or more jobs with a status code of
   'successful-ok' if there had been jobs matching the criteria, then
   the status code for 0 jobs MUST be 'successful-ok'.

   Group 1: Operation Attributes

      Status Message:
        In addition to the REQUIRED status code returned in every
        response, the response OPTIONALLY includes a "status-message"
        (text(255)) and/or a "detailed-status-message" (text(MAX))
        operation attribute as described in sections 13 and 3.1.6.

      Natural Language and Character Set:
        The "attributes-charset" and "attributes-natural-language"
        attributes as described in section 3.1.4.2.







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   Group 2: Unsupported Attributes

      See section 3.1.7 for details on returning Unsupported Attributes.

      The response NEED NOT contain the "requested-attributes" operation
      attribute with any supplied values (attribute keywords) that were
      requested by the client but are not supported by the IPP object.
      If the Printer object does return unsupported attributes
      referenced in the "requested-attributes" operation attribute and
      that attribute included group names, such as 'all', the
      unsupported attributes MUST NOT include attributes described in
      the standard but not supported by the implementation.

   Groups 3 to N: Job Object Attributes

      The Printer object responds with one set of Job Object Attributes
      for each returned Job object.  The Printer object ignores (does
      not respond with) any requested attribute or value which is not
      supported or which is restricted by the security policy in force,
      including whether the requesting user is the user that submitted
      the job (job originating user) or not (see section 8).  However,
      the Printer object MUST respond with the 'unknown' value for any
      supported attribute (including all REQUIRED attributes) for which
      the Printer object does not know the value, unless it would
      violate the security policy.  See the description of the "out-of-
      band" values in the beginning of Section 4.1.

      Jobs are returned in the following order:

      - If the client requests all 'completed' Jobs (Jobs in the
        'completed', 'aborted', or 'canceled' states), then the Jobs are
        returned newest to oldest (with respect to actual completion
        time)
      - If the client requests all 'not-completed' Jobs (Jobs in the
        'pending', 'processing', 'pending-held', and 'processing-
        stopped' states), then Jobs are returned in relative
        chronological order of expected time to complete (based on
        whatever scheduling algorithm is configured for the Printer
        object).

3.2.7 Pause-Printer Operation

   This OPTIONAL operation allows a client to stop the Printer object
   from scheduling jobs on all its devices.  Depending on
   implementation, the Pause-Printer operation MAY also stop the Printer
   from processing the current job or jobs.  Any job that is currently
   being printed is either stopped as soon as the implementation permits




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   or is completed, depending on implementation.  The Printer object
   MUST still accept create operations to create new jobs, but MUST
   prevent any jobs from entering the 'processing' state.

   If the Pause-Printer operation is supported, then the Resume-Printer
   operation MUST be supported, and vice-versa.

   The IPP Printer stops the current job(s) on its device(s) that were
   in the 'processing' or 'processing-stopped' states as soon as the
   implementation permits.  If the implementation will take appreciable
   time to stop, the IPP Printer adds the 'moving-to-paused' value to
   the Printer object's "printer-state-reasons" attribute (see section
   4.4.12).  When the device(s) have all stopped, the IPP Printer
   transitions the Printer object to the 'stopped' state, removes the
   'moving-to-paused' value, if present, and adds the 'paused' value to
   the Printer object's "printer-state-reasons" attribute.

   When the current job(s) complete that were in the 'processing' state,
   the IPP Printer transitions them to the 'completed' state.  When the
   current job(s) stop in mid processing that were in the 'processing'
   state, the IPP Printer transitions them to the 'processing-stopped'
   state and adds the 'printer-stopped' value to the job's "job-state-
   reasons" attribute.

   For any jobs that are 'pending' or 'pending-held', the 'printer-
   stopped' value of the jobs' "job-state-reasons" attribute also
   applies.  However, the IPP Printer NEED NOT update those jobs' "job-
   state-reasons" attributes and only need return the 'printer-stopped'
   value when those jobs are queried (so-called "lazy evaluation").

   Whether the Pause-Printer operation affects jobs that were submitted
   to the device from other sources than the IPP Printer object in the
   same way that the Pause-Printer operation affects jobs that were
   submitted to the IPP Printer object using IPP, depends on
   implementation, i.e., on whether the IPP protocol is being used as a
   universal management protocol or just to manage IPP jobs,
   respectively.

   The IPP Printer MUST accept the request in any state and transition
   the Printer to the indicated new "printer-state" before returning as
   follows:










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     Current        New      "printer   IPP Printer's response status
    "printer-    "printer-   -state-          code and action:
     state"       state"    reasons"

  'idle'       'stopped'    'paused'  'successful-ok'
  'processing' 'processing' 'moving-  OPTION 1: 'successful-ok';
                              to-       Later, when all output has
                              paused'   stopped, the "printer-state"
                                        becomes 'stopped', and the
                                        'paused' value replaces the
                                        'moving-to-paused' value in the
                                        "printer-state-reasons"
                                        attribute
  'processing' 'stopped'    'paused'  OPTION 2: 'successful-ok';
                                        all device output stopped
                                        immediately
  'stopped'    'stopped'    'paused'  'successful-ok'

   Access Rights: The authenticated user (see section 8.3) performing
   this operation must be an operator or administrator of the Printer
   object (see Sections 1 and 8.5).   Otherwise, the IPP Printer MUST
   reject the operation and return:  'client-error-forbidden', 'client-
   error-not-authenticated', or 'client-error-not-authorized' as
   appropriate.

3.2.7.1 Pause-Printer Request

   The following groups of attributes are part of the Pause-Printer
   Request:

   Group 1: Operation Attributes

      Natural Language and Character Set:
        The "attributes-charset" and "attributes-natural-language"
        attributes as described in section 3.1.4.1.

      Target:
        The "printer-uri" (uri) operation attribute which is the target
        for this operation as described in section 3.1.5.

      Requesting User Name:
        The "requesting-user-name" (name(MAX)) attribute SHOULD be
        supplied by the client as described in section 8.3.








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3.2.7.2 Pause-Printer Response

   The following groups of attributes are part of the Pause-Printer
   Response:

   Group 1: Operation Attributes

      Status Message:
        In addition to the REQUIRED status code returned in every
        response, the response OPTIONALLY includes a "status-message"
        (text(255)) and/or a "detailed-status-message" (text(MAX))
        operation attribute as described in sections 13 and  3.1.6.

      Natural Language and Character Set:
        The "attributes-charset" and "attributes-natural-language"
        attributes as described in section 3.1.4.2.

   Group 2: Unsupported Attributes

      See section 3.1.7 for details on returning Unsupported Attributes.

3.2.8 Resume-Printer Operation

   This operation allows a client to resume the Printer object
   scheduling jobs on all its devices.  The Printer object MUST remove
   the 'paused' and 'moving-to-paused' values from the Printer object's
   "printer-state-reasons" attribute, if present.  If there are no other
   reasons to keep a device paused (such as media-jam), the IPP Printer
   is free to transition itself to the 'processing' or 'idle' states,
   depending on whether there are jobs to be processed or not,
   respectively, and the device(s) resume processing jobs.

   If the Pause-Printer operation is supported, then the Resume-Printer
   operation MUST be supported, and vice-versa.

   The IPP Printer removes the 'printer-stopped' value from any job's
   "job-state-reasons" attributes contained in that Printer.

   The IPP Printer MUST accept the request in any state, transition the
   Printer object to the indicated new state as follows:











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     Current    New "printer-  IPP Printer's response status code and
    "printer-      state"                     action:
      state"

   'idle'       'idle'         'successful-ok'
   'processing' 'processing'   'successful-ok'

   'stopped'    'processing'   'successful-ok';
                               when there are jobs to be processed
   'stopped'    'idle'         'successful-ok';
                               when there are no jobs to be processed.

   Access Rights: The authenticated user (see section 8.3) performing
   this operation must be an operator or administrator of the Printer
   object (see Sections 1 and 8.5).  Otherwise, the IPP Printer MUST
   reject the operation and return:  'client-error-forbidden', 'client-
   error-not-authenticated', or 'client-error-not-authorized' as
   appropriate.

   The Resume-Printer Request and Resume-Printer Response have the same
   attribute groups and attributes as the Pause-Printer operation (see
   sections 3.2.7.1 and 3.2.7.2).

3.2.9 Purge-Jobs Operation

   This OPTIONAL operation allows a client to remove all jobs from an
   IPP Printer object, regardless of their job states, including jobs in
   the Printer object's Job History (see Section 4.3.7.2).  After a
   Purge-Jobs operation has been performed, a Printer object MUST return
   no jobs in subsequent Get-Job-Attributes and Get-Jobs responses
   (until new jobs are submitted).

   Whether the Purge-Jobs (and Get-Jobs) operation affects jobs that
   were submitted to the device from other sources than the IPP Printer
   object in the same way that the Purge-Jobs operation affects jobs
   that were submitted to the IPP Printer object using IPP, depends on
   implementation, i.e., on whether the IPP protocol is being used as a
   universal management protocol or just to manage IPP jobs,
   respectively.

   Note:  if an operator wants to cancel all jobs without clearing out
   the Job History, the operator uses the Cancel-Job operation on each
   job instead of using the Purge-Jobs operation.

   The Printer object MUST accept this operation in any state and
   transition the Printer object to the 'idle' state.





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   Access Rights: The authenticated user (see section 8.3) performing
   this operation must be an operator or administrator of the Printer
   object (see Sections 1 and 8.5).  Otherwise, the IPP object MUST
   reject the operation and return: client-error-forbidden, client-
   error-not-authenticated, and client-error-not-authorized as
   appropriate.

   The Purge-Jobs Request and Purge-Jobs Response have the same
   attribute groups and attributes as the Pause-Printer operation (see
   sections 3.2.7.1 and 3.2.7.2).

3.3 Job Operations

   All Job operations are directed at Job objects.  A client MUST always
   supply some means of identifying the Job object in order to identify
   the correct target of the operation.  That job identification MAY
   either be a single Job URI or a combination of a Printer URI with a
   Job ID.  The IPP object implementation MUST support both forms of
   identification for every job.

3.3.1 Send-Document Operation

   This OPTIONAL operation allows a client to create a multi-document
   Job object that is initially "empty" (contains no documents).  In the
   Create-Job response, the Printer object returns the Job object's URI
   (the "job-uri" attribute) and the Job object's 32-bit identifier (the
   "job-id" attribute).  For each new document that the client desires
   to add, the client uses a Send-Document operation.  Each Send-
   Document Request contains the entire stream of document data for one
   document.

   If the Printer supports this operation but does not support multiple
   documents per job, the Printer MUST reject subsequent Send-Document
   operations supplied with data and return the 'server-error-multiple-
   document-jobs-not-supported'.  However, the Printer MUST accept the
   first document with a 'true' or 'false' value for the "last-document"
   operation attribute (see below), so that clients MAY always submit
   one document jobs with a 'false' value for "last-document" in the
   first Send-Document and a 'true' for "last-document" in the second
   Send-Document (with no data).

   Since the Create-Job and the send operations (Send-Document or Send-
   URI operations) that follow could occur over an arbitrarily long
   period of time for a particular job, a client MUST send another send
   operation within an IPP Printer defined minimum time interval after
   the receipt of the previous request for the job.  If a Printer object
   supports the Create-Job and Send-Document operations, the Printer
   object MUST support the "multiple-operation-time-out" attribute (see



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   section 4.4.31).  This attribute indicates the minimum number of
   seconds the Printer object will wait for the next send operation
   before taking some recovery action.

   An IPP object MUST recover from an errant client that does not supply
   a send operation, sometime after the minimum time interval specified
   by the Printer object's "multiple-operation-time-out" attribute.
   Such recovery MAY include any of the following or other recovery
   actions:

      1. Assume that the Job is an invalid job, start the process of
         changing the job state to 'aborted', add the 'aborted-by-
         system' value to the job's "job-state-reasons" attribute (see
         section 4.3.8), and clean up all resources associated with the
         Job.  In this case, if another send operation is finally
         received, the Printer responds with an "client-error-not-
         possible" or "client-error-not-found" depending on whether or
         not the Job object is still around when the send operation
         finally arrives.
      2. Assume that the last send operation received was in fact the
         last document (as if the "last-document" flag had been set to
         'true'), close the Job object, and proceed to process it (i.e.,
         move the Job's state to 'pending').
      3. Assume that the last send operation received was in fact the
         last document, close the Job, but move it to the 'pending-held'
         and add the 'submission-interrupted' value to the job's "job-
         state-reasons" attribute (see section 4.3.8).  This action
         allows the user or an operator to determine whether to continue
         processing the Job by moving it back to the 'pending' state
         using the Release-Job operation (see section 3.3.6) or to
         cancel the job using the Cancel-Job operation (see section
         3.3.3).

   Each implementation is free to decide the "best" action to take
   depending on local policy, whether any documents have been added,
   whether the implementation spools jobs or not,  and/or any other
   piece of information available to it.  If the choice is to abort the
   Job object, it is possible that the Job object may already have been
   processed to the point that some media sheet pages have been printed.

   Access Rights: The authenticated user (see section 8.3) performing
   this operation must either be the job owner (as determined in the
   Create-Job operation) or an operator or administrator of the Printer
   object (see Sections 1 and 8.5).  Otherwise, the IPP object MUST
   reject the operation and return: 'client-error-forbidden', 'client-
   error-not-authenticated', or 'client-error-not-authorized' as
   appropriate.




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3.3.1.1 Send-Document Request

   The following attribute sets are part of the Send-Document Request:

   Group 1: Operation Attributes

      Natural Language and Character Set:
        The "attributes-charset" and "attributes-natural-language"
        attributes as described in section 3.1.4.1.

      Target:
        Either (1) the "printer-uri" (uri) plus "job-id"
        (integer(1:MAX))or (2) the "job-uri" (uri) operation
        attribute(s) which define the target for this operation as
        described in section 3.1.5.

      Requesting User Name:
        The "requesting-user-name" (name(MAX)) attribute SHOULD be
        supplied by the client as described in section 8.3.

      "document-name" (name(MAX)):
        The client OPTIONALLY supplies this attribute.  The Printer
        object MUST support this attribute.  It contains the client
        supplied document name.  The document name MAY be different than
        the Job name.  It might be helpful, but NEED NOT be unique
        across multiple documents in the same Job.  Typically, the
        client software automatically supplies the document name on
        behalf of the end user by using a file name or an application
        generated name.  See the description of the "document-name"
        operation attribute in the Print-Job Request (section 3.2.1.1)
        for more information about this attribute.

      "compression" (type3 keyword):
        See the description of "compression" for the Print-Job operation
        in Section 3.2.1.1.

      "document-format" (mimeMediaType):
        See the description of "document-format" for the Print-Job
        operation in Section 3.2.1.1.

      "document-natural-language" (naturalLanguage):
        The client OPTIONALLY supplies this attribute.  The Printer
        object OPTIONALLY supports this attribute.  This attribute
        specifies the natural language of the document for those
        document-formats that require a specification of the natural
        language in order to image the document unambiguously.  There
        are no particular values required for the Printer object to
        support.



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      "last-document" (boolean):
        The client MUST supply this attribute.  The Printer object MUST
        support this attribute. It is a boolean flag that is set to
        'true' if this is the last document for the Job, 'false'
        otherwise.

   Group 2: Document Content

      The client MUST supply the document data if the "last-document"
      flag is set to 'false'.  However, since a client might not know
      that the previous document sent with a Send-Document (or Send-URI)
      operation was the last document (i.e., the "last-document"
      attribute was set to 'false'), it is legal to send a Send-Document
      request with no document data where the "last-document" flag is
      set to 'true'.  Such a request MUST NOT increment the value of the
      Job object's "number-of-documents" attribute, since no real
      document was added to the job.  It is not an error for a client to
      submit a job with no actual document data, i.e., only a single
      Create-Job and Send-Document request with a "last-document"
      operation attribute set to 'true' with no document data.

3.3.1.2 Send-Document Response

   The following sets of attributes are part of the Send-Document
   Response:

   Group 1: Operation Attributes

      Status Message:
         In addition to the REQUIRED status code returned in every
         response, the response OPTIONALLY includes a "status-message"
         (text(255)) and/or a "detailed-status-message" (text(MAX))
         operation attribute as described in sections 13 and 3.1.6.

      Natural Language and Character Set:
         The "attributes-charset" and "attributes-natural-language"
         attributes as described in section 3.1.4.2.

   Group 2: Unsupported Attributes

      See section 3.1.7 for details on returning Unsupported Attributes.

   Group 3: Job Object Attributes

      This is the same set of attributes as described in the Print-Job
      response (see section 3.2.1.2).





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3.3.2 Send-URI Operation

   This OPTIONAL operation is identical to the Send-Document operation
   (see section 3.3.1) except that a client MUST supply a URI reference
   ("document-uri" operation attribute) rather than the document data
   itself.  If a Printer object supports this operation, clients can use
   both Send-URI or Send-Document operations to add new documents to an
   existing multi-document Job object.  However, if a client needs to
   indicate that the previous Send-URI or Send-Document was the last
   document,  the client MUST use the Send-Document operation with no
   document data and the "last-document" flag set to 'true' (rather than
   using a Send-URI operation with no "document-uri" operation
   attribute).

   If a Printer object supports this operation, it MUST also support the
   Print-URI operation (see section 3.2.2).

   The Printer object MUST validate the syntax and URI scheme of the
   supplied URI before returning a response, just as in the Print-URI
   operation.  The IPP Printer MAY validate the accessibility of the
   document as part of the operation or subsequently (see section
   3.2.2).

3.3.3 Cancel-Job Operation

   This REQUIRED operation allows a client to cancel a Print Job from
   the time the job is created up to the time it is completed, canceled,
   or aborted.  Since a Job might already be printing by the time a
   Cancel-Job is received, some media sheet pages might be printed
   before the job is actually terminated.

   The IPP object MUST accept or reject the request based on the job's
   current state and transition the job to the indicated new state as
   follows:

















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       Current "job-    New "job-     IPP object's response status
           state"         state"             code and action:

      'pending'       'canceled'     'successful-ok'
      'pending-held'  'canceled'     'successful-ok'
      'processing'    'canceled'     'successful-ok'
      'processing'    'processing'   'successful-ok'  See Rule 1
      'processing'    'processing'   'client-error-not-possible'
                                     See Rule 2
      'processing-    'canceled'     'successful-ok'
      stopped'
      'processing-    'processing-   'successful-ok'  See Rule 1
      stopped'        stopped'
      'processing-    'processing-   'client-error-not-possible'
      stopped'        stopped'       See Rule 2
      'completed'     'completed'    'client-error-not-possible'
      'canceled'      'canceled'     'client-error-not-possible'
      'aborted'       'aborted'      'client-error-not-possible'

   Rule 1:  If the implementation requires some measurable time to
   cancel the job in the 'processing' or 'processing-stopped' job
   states, the IPP object MUST add the 'processing-to-stop-point' value
   to the job's "job-state-reasons" attribute and then transition the
   job to the 'canceled' state when the processing ceases (see section
   4.3.8).

   Rule 2:  If the Job object already has the 'processing-to-stop-point'
   value in its "job-state-reasons" attribute, then the Printer object
   MUST reject a Cancel-Job operation.

   Access Rights: The authenticated user (see section 8.3) performing
   this operation must either be the job owner or an operator or
   administrator of the Printer object (see Sections 1 and 8.5).
   Otherwise, the IPP object MUST reject the operation and return:
    'client-error-forbidden', 'client-error-not-authenticated', or
   'client-error-not-authorized' as appropriate.

3.3.3.1 Cancel-Job Request

   The following groups of attributes are part of the Cancel-Job
   Request:

   Group 1: Operation Attributes

      Natural Language and Character Set:
         The "attributes-charset" and "attributes-natural-language"
         attributes as described in section 3.1.4.1.




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      Target:
         Either (1) the "printer-uri" (uri) plus "job-id"
         (integer(1:MAX))or (2) the "job-uri" (uri) operation
         attribute(s) which define the target for this operation as
         described in section 3.1.5.

      Requesting User Name:
         The "requesting-user-name" (name(MAX)) attribute SHOULD be
         supplied by the client as described in section 8.3.

      "message" (text(127)):
         The client OPTIONALLY supplies this attribute.  The Printer
         object OPTIONALLY supports this attribute. It is a message to
         the operator.  This "message" attribute is not the same as the
         "job-message-from-operator" attribute.  That attribute is used
         to report a message from the operator to the end user that
         queries that attribute.  This "message" operation attribute is
         used to send a message from the client to the operator along
         with the operation request.  It is an implementation decision
         of how or where to display this message to the operator (if at
         all).

3.3.3.2 Cancel-Job Response

   The following sets of attributes are part of the Cancel-Job Response:

   Group 1: Operation Attributes

      Status Message:
         In addition to the REQUIRED status code returned in every
         response, the response OPTIONALLY includes a "status-message"
         (text(255)) and/or a "detailed-status-message" (text(MAX))
         operation attribute as described in sections 13 and 3.1.6.

      Natural Language and Character Set:
         The "attributes-charset" and "attributes-natural-language"
         attributes as described in section 3.1.4.2.

   Group 2: Unsupported Attributes

      See section 3.1.7 for details on returning Unsupported Attributes.

   Once a successful response has been sent, the implementation
   guarantees that the Job will eventually end up in the 'canceled'
   state. Between the time of the Cancel-Job operation is accepted and
   when the job enters the 'canceled' job-state (see section 4.3.7), the
   "job-state-reasons" attribute SHOULD contain the 'processing-to-
   stop-point'



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   value which indicates to later queries that although the Job might
   still be 'processing', it will eventually end up in the
   'canceled' state, not the 'completed' state.

3.3.4 Get-Job-Attributes Operation

   This REQUIRED operation allows a client to request the values of
   attributes of a Job object and it is almost identical to the Get-
   Printer-Attributes operation (see section 3.2.5).  The only
   differences are that the operation is directed at a Job object rather
   than a Printer object, there is no "document-format" operation
   attribute used when querying a Job object, and the returned attribute
   group is a set of Job object attributes rather than a set of Printer
   object attributes.

   For Jobs, the possible names of attribute groups are:

      - 'job-template': the subset of the Job Template attributes that
        apply to a Job object (the first column of the table in Section
        4.2) that the implementation supports for Job objects.
      - 'job-description': the subset of the Job Description attributes
        specified in Section 4.3 that the implementation supports for
        Job objects.
      - 'all': the special group 'all' that includes all attributes that
        the implementation supports for Job objects.

   Since a client MAY request specific attributes or named groups, there
   is a potential that there is some overlap.  For example, if a client
   requests, 'job-name' and 'job-description', the client is actually
   requesting the "job-name" attribute once by naming it explicitly, and
   once by inclusion in the 'job-description' group.  In such cases, the
   Printer object NEED NOT return the attribute only once in the
   response even if it is requested multiple times.  The client SHOULD
   NOT request the same attribute in multiple ways.

   It is NOT REQUIRED that a Job object support all attributes belonging
   to a group (since some attributes are OPTIONAL).  However it is
   REQUIRED that each Job object support all these group names.

3.3.4.1 Get-Job-Attributes Request

   The following groups of attributes are part of the Get-Job-Attributes
   Request when the request is directed at a Job object:








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   Group 1: Operation Attributes

      Natural Language and Character Set:
        The "attributes-charset" and "attributes-natural-language"
        attributes as described in section 3.1.4.1.

      Target:
        Either (1) the "printer-uri" (uri) plus "job-id"
        (integer(1:MAX)) or (2) the "job-uri" (uri) operation
        attribute(s) which define the target for this operation as
        described in section 3.1.5.

      Requesting User Name:
        The "requesting-user-name" (name(MAX)) attribute SHOULD be
        supplied by the client as described in section 8.3.

      "requested-attributes" (1setOf keyword):
        The client OPTIONALLY supplies this attribute.  The IPP object
        MUST support this attribute.   It is a set of attribute names
        and/or attribute group names in whose values the requester is
        interested.  If the client omits this attribute, the IPP object
        MUST respond as if this attribute had been supplied with a value
        of 'all'.

3.3.4.2 Get-Job-Attributes Response

   The Printer object returns the following sets of attributes as part
   of the Get-Job-Attributes Response:

   Group 1: Operation Attributes

      Status Message:
         In addition to the REQUIRED status code returned in every
         response, the response OPTIONALLY includes a "status-message"
         (text(255)) and/or a "detailed-status-message" (text(MAX))
         operation attribute as described in sections 13 and 3.1.6.

      Natural Language and Character Set:
         The "attributes-charset" and "attributes-natural-language"
         attributes as described in section 3.1.4.2.  The "attributes-
         natural-language" MAY be the natural language of the Job
         object, rather than the one requested.

   Group 2: Unsupported Attributes

      See section 3.1.7 for details on returning Unsupported Attributes.





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      The response NEED NOT contain the "requested-attributes" operation
      attribute with any supplied values (attribute keywords) that were
      requested by the client but are not supported by the IPP object.
      If the Printer object does return unsupported attributes
      referenced in the "requested-attributes" operation attribute and
      that attribute included group names, such as 'all', the
      unsupported attributes MUST NOT include attributes described in
      the standard but not supported by the implementation.

   Group 3: Job Object Attributes

      This is the set of requested attributes and their current values.
      The IPP object ignores (does not respond with) any requested
      attribute or value which is not supported or which is restricted
      by the security policy in force, including whether the requesting
      user is the user that submitted the job (job originating user) or
      not (see section 8).  However, the IPP object MUST respond with
      the 'unknown' value for any supported attribute (including all
      REQUIRED attributes) for which the IPP object does not know the
      value, unless it would violate the security policy.  See the
      description of the "out-of-band" values in the beginning of
      Section 4.1.

3.3.5 Hold-Job Operation

   This OPTIONAL operation allows a client to hold a pending job in the
   queue so that it is not eligible for scheduling.  If the Hold-Job
   operation is supported, then the Release-Job operation MUST be
   supported, and vice-versa.  The OPTIONAL "job-hold-until" operation
   attribute allows a client to specify whether to hold the job
   indefinitely or until a specified time period, if supported.

   The IPP object MUST accept or reject the request based on the job's
   current state and transition the job to the indicated new state as
   follows:
















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        Current "job-     New "job-state"   IPP object's response status
            state"                                 code and action:

      'pending'         'pending-held'     'successful-ok'  See Rule 1
      'pending'         'pending'          'successful-ok'  See Rule 2
      'pending-held'    'pending-held'     'successful-ok'  See Rule 1
      'pending-held'    'pending'          'successful-ok'  See Rule 2
      'processing'      'processing'       'client-error-not-possible'
      'processing-      'processing-       'client-error-not-possible'
      stopped'          stopped'
      'completed'       'completed'        'client-error-not-possible'
      'canceled'        'canceled'         'client-error-not-possible'
      'aborted'         'aborted'          'client-error-not-possible'

   Rule 1:  If the implementation supports multiple reasons for a job to
   be in the 'pending-held' state, the IPP object MUST add the 'job-
   hold-until-specified' value to the job's "job-state-reasons"
   attribute.

   Rule 2:  If the IPP object supports the "job-hold-until" operation
   attribute, but the specified time period has already started (or is
   the 'no-hold' value) and there are no other reasons to hold the job,
   the IPP object MUST make the job be a candidate for processing
   immediately (see Section 4.2.2) by putting the job in the 'pending'
   state.

   Note:  In order to keep the Hold-Job operation simple, such a request
   is rejected when the job is in the 'processing' or 'processing-
   stopped' states.  If an operation is needed to hold jobs while in
   these states, it will be added as an additional operation, rather
   than overloading the Hold-Job operation.  Then it is clear to clients
   by querying the Printer object's "operations-supported" (see Section
   4.4.15) and the Job object's "job-state" (see Section 4.3.7)
   attributes which operations are possible.

   Access Rights: The authenticated user (see section 8.3) performing
   this operation must either be the job owner or an operator or
   administrator of the Printer object (see Sections 1 and 8.5).
   Otherwise, the IPP object MUST reject the operation and return:
   'client-error-forbidden', 'client-error-not-authenticated', or
   'client-error-not-authorized' as appropriate.

3.3.5.1 Hold-Job Request

   The groups and operation attributes are the same as for a Cancel-Job
   request (see section 3.3.3.1), with the addition of the following
   Group 1 Operation attribute:




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      "job-hold-until" (type3 keyword | name(MAX)):
         The client OPTIONALLY supplies this Operation attribute.  The
         IPP object MUST support this operation attribute in a Hold-Job
         request, if it supports the "job-hold-until" Job template
         attribute in create operations.  See section 4.2.2.  The IPP
         object SHOULD support the "job-hold-until" Job Template
         attribute for use in job create operations with at least the
         'indefinite' value, if it supports the Hold-Job operation.
         Otherwise, a client cannot create a job and hold it immediately
         (without picking some supported time period in the future).

         If supplied and supported as specified in the Printer's "job-
         hold-until-supported" attribute, the IPP object copies the
         supplied operation attribute to the Job object, replacing the
         job's previous "job-hold-until" attribute, if present, and
         makes the job a candidate for scheduling during the supplied
         named time period.

         If supplied, but either the "job-hold-until" Operation
         attribute itself or the value supplied is not supported, the
         IPP object accepts the request, returns the unsupported
         attribute or value in the Unsupported Attributes Group
         according to section 3.1.7, returns the 'successful-ok-
         ignored-or-substituted-attributes, and holds the job
         indefinitely until a client performs a subsequent Release-Job
         operation.

         If the client (1) supplies a value that specifies a time period
         that has already started or the 'no-hold' value (meaning don't
         hold the job) and (2) the IPP object supports the "job-hold-
         until" operation attribute and there are no other reasons to
         hold the job, the IPP object MUST accept the operation and make
         the job be a candidate for processing immediately (see Section
         4.2.2).

         If the client does not supply a "job-hold-until" Operation
         attribute in the request, the IPP object MUST populate the job
         object with a "job-hold-until" attribute with the 'indefinite'
         value (if IPP object supports the "job-hold-until" attribute)
         and hold the job indefinitely, until a client performs a
         Release-Job operation.

3.3.5.2 Hold-Job Response

   The groups and attributes are the same as for a Cancel-Job response
   (see section 3.3.3.2).





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3.3.6 Release-Job Operation

   This OPTIONAL operation allows a client to release a previously held
   job so that it is again eligible for scheduling.  If the Hold-Job
   operation is supported, then the Release-Job operation MUST be
   supported, and vice-versa.

   This operation removes the "job-hold-until" job attribute, if
   present, from the job object that had been supplied in the create or
   most recent Hold-Job or Restart-Job operation and removes its effect
   on the job.  The IPP object MUST remove the 'job-hold-until-
   specified' value from the job's "job-state-reasons" attribute, if
   present.  See section 4.3.8.

   The IPP object MUST accept or reject the request based on the job's
   current state and transition the job to the indicated new state as
   follows:

        Current "job-   New "job-state"    IPP object's response status
           state"                                code and action:

      'pending'        'pending'        'successful-ok'
                                         No effect on the job.
      'pending-held'   'pending-held'   'successful-ok'  See Rule 1
      'pending-held'   'pending'        'successful-ok'
      'processing'     'processing'     'successful-ok'
                                         No effect on the job.
      'processing-     'processing-     'successful-ok'
       stopped'         stopped'         No effect on the job.
      'completed'      'completed'      'client-error-not-possible'
      'canceled'       'canceled'       'client-error-not-possible'
      'aborted'        'aborted'        'client-error-not-possible'

   Rule 1:  If there are other reasons to keep the job in the 'pending-
   held' state, such as 'resources-are-not-ready', the job remains in
   the 'pending-held' state.  Thus the 'pending-held' state is not just
   for jobs that have the 'job-hold-until' applied to them, but are for
   any reason to keep the job from being a candidate for scheduling and
   processing, such as 'resources-are-not-ready'.  See the "job-hold-
   until" attribute (section 4.2.2).

   Access Rights: The authenticated user (see section 8.3) performing
   this operation must either be the job owner or an operator or
   administrator of the Printer object (see Sections 1 and 8.5).
   Otherwise, the IPP object MUST reject the operation and return:
   'client-error-forbidden', 'client-error-not-authenticated', or
   'client-error-not-authorized' as appropriate.




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   The Release-Job Request and Release-Job Response have the same
   attribute groups and attributes as the Cancel-Job operation (see
   section 3.3.3.1 and 3.3.3.2).

3.3.7 Restart-Job Operation

   This OPTIONAL operation allows a client to restart a job that is
   retained in the queue after processing has completed (see section
   4.3.7.2).

   The job is moved to the 'pending' or 'pending-held' job state and
   restarts at the beginning on the same IPP Printer object with the
   same attribute values.  If any of the documents in the job were
   passed by reference (Print-URI or Send-URI), the Printer MUST re-
   fetch the data, since the semantics of Restart-Job are to repeat all
   Job processing.  The Job Description attributes that accumulate job
   progress, such as "job-impressions-completed", "job-media-sheets-
   completed", and "job-k-octets-processed", MUST be reset to 0 so that
   they give an accurate record of the job from its restart point.  The
   job object MUST continue to use the same "job-uri" and "job-id"
   attribute values.

   Note:  If in the future an operation is needed that does not reset
   the job progress attributes, then a new operation will be defined
   which makes a copy of the job, assigns a new "job-uri" and "job-id"
   to the copy and resets the job progress attributes in the new copy
   only.

   The IPP object MUST accept or reject the request based on the job's
   current state, transition the job to the indicated new state as
   follows:




















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        Current "job-   New "job-state"    IPP object's response status
           state"                                code and action:

      'pending'        'pending'        'client-error-not-possible'
      'pending-held'   'pending-held'   'client-error-not-possible'
      'processing'     'processing'     'client-error-not-possible'
      'processing-     'processing-     'client-error-not-possible'
      stopped'         stopped'
      'completed'      'pending' or     'successful-ok' - job is started
                        'pending-held'   over.
      'completed'      'completed'      'client-error-not-possible' -
                                         see Rule 1
      'canceled'       'pending' or     'successful-ok' - job is started
                        'pending-held'   over.
      'canceled'       'canceled'       'client-error-not-possible' -
                                         see Rule 1
      'aborted'        'pending' or     'successful-ok' - job is started
                        'pending-held'   over.
      'aborted'        'aborted'        'client-error-not-possible' -
                                         see Rule 1

   Rule 1:  If the Job Retention Period has expired for the job in this
   state, then the IPP object rejects the operation.  See section
   4.3.7.2.

   Note:  In order to prevent a user from inadvertently restarting a job
   in the middle, the Restart-Job request is rejected when the job is in
   the 'processing' or 'processing-stopped' states.  If in the future an
   operation is needed to hold or restart jobs while in these states, it
   will be added as an additional operation, rather than overloading the
   Restart-Job operation, so that it is clear that the user intended
   that the current job not be completed.

   Access Rights: The authenticated user (see section 8.3) performing
   this operation must either be the job owner or an operator or
   administrator of the Printer object (see Sections 1 and 8.5).
   Otherwise, the IPP object MUST reject the operation and return:
   'client-error-forbidden', 'client-error-not-authenticated', or
   'client-error-not-authorized' as appropriate.

3.3.7.1 Restart-Job Request

   The groups and attributes are the same as for a Cancel-Job request
   (see section 3.3.3.1), with the addition of the following Group 1
   Operation attribute:






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      "job-hold-until" (type3 keyword | name(MAX)):
         The client OPTIONALLY supplies this attribute.  The IPP object
         MUST support this Operation attribute in a Restart-Job request,
         if it supports the "job-hold-until" Job Template attribute in
         create operations.  See section 4.2.2.  Otherwise, the IPP
         object NEED NOT support the "job-hold-until" Operation
         attribute in a Restart-Job request.

         If supplied and supported as specified in the Printer's "job-
         hold-until-supported" attribute, the IPP object copies the
         supplied Operation attribute to the Job object, replacing the
         job's previous "job-hold-until" attribute, if present, and
         makes the job a candidate for scheduling during the supplied
         named time period.  See section 4.2.2.

         If supplied, but the value is not supported, the IPP object
         accepts the request, returns the unsupported attribute or value
         in the Unsupported Attributes Group according to section 3.1.7,
         returns the 'successful-ok-ignored-or-substituted-attributes'
         status code, and holds the job indefinitely until a client
         performs a subsequent Release-Job operation.

         If supplied, but the "job-hold-until" Operation attribute
         itself is not supported, the IPP object accepts the request,
         returns the unsupported attribute with the out-of-band
         'unsupported' value in the Unsupported Attributes Group
         according to section 3.1.7, returns the 'successful-ok-
         ignored-or-substituted-attributes' status code, and restarts
         the job, i.e., ignores the "job-hold-until" attribute.

         If the client (1) supplies a value that specifies a time period
         that has already started or the 'no-hold' value (meaning don't
         hold the job) and (2) the IPP object supports the "job-hold-
         until" operation attribute and there are no other reasons to
         hold the job, the IPP object makes the job a candidate for
         processing immediately (see Section 4.2.2).

         If the client does not supply a "job-hold-until" operation
         attribute in the request, the IPP object removes the "job-
         hold-until" attribute, if present, from the job.  If there are
         no other reasons to hold the job, the Restart-Job operation
         makes the job a candidate for processing immediately (see
         Section 4.2.2).








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3.3.7.2 Restart-Job Response

   The groups and attributes are the same as for a Cancel-Job response
   (see section 3.3.3.2).

   Note:  In the future an OPTIONAL Modify-Job or Set-Job-Attributes
   operation may be specified that allows the client to modify other
   attributes before releasing the restarted job.

4. Object Attributes

   This section describes the attributes with their corresponding
   attribute syntaxes and values that are part of the IPP model.  The
   sections below show the objects and their associated attributes which
   are included within the scope of this protocol.  Many of these
   attributes are derived from other relevant documents:

      - Document Printing Application (DPA) [ISO10175]
      - RFC 1759 Printer MIB [RFC1759]

   Each attribute is uniquely identified in this document using a
   "keyword" (see section 12.2.1) which is the name of the attribute.
   The keyword is included in the section header describing that
   attribute.

   Note:  Not only are keywords used to identify attributes, but one of
   the attribute syntaxes described below is "keyword" so that some
   attributes have keyword values.  Therefore, these attributes are
   defined as having an attribute syntax that is a set of keywords.

4.1 Attribute Syntaxes

   This section defines the basic attribute syntax types that all
   clients and IPP objects MUST be able to accept in responses and
   accept in requests, respectively.  Each attribute description in
   sections 3 and 4 includes the name of attribute syntax(es) in the
   heading (in parentheses).  A conforming implementation of an
   attribute MUST include the semantics of the attribute syntax(es) so
   identified.  Section 6.3 describes how the protocol can be extended
   with new attribute syntaxes.

   The attribute syntaxes are specified in the following sub-sections,
   where the sub-section heading is the keyword name of the attribute
   syntax inside the single quotes.  In operation requests and responses
   each attribute value MUST be represented as one of the attribute
   syntaxes specified in the sub-section heading for the attribute.  In
   addition, the value of an attribute in a response (but not in a




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   request) MAY be one of the "out-of-band" values whose special
   encoding rules are defined in the "Encoding and Transport" document
   [RFC2910].   Standard "out-of-band" values are:

      'unknown': The attribute is supported by the IPP object, but the
         value is unknown to the IPP object for some reason.
      'unsupported': The attribute is unsupported by the IPP object.
         This value MUST be returned only as the value of an attribute
         in the Unsupported Attributes Group.
      'no-value': The attribute is supported by the Printer object, but
         the administrator has not yet configured a value.

   All attributes in a request MUST have one or more values as defined
   in Sections 4.2 to 4.4.  Thus clients MUST NOT supply attributes with
   "out-of-band" values for operations defined in this document.  All
   attributes in a response MUST have one or more values as defined in
   Sections 4.2 to 4.4 or a single "out-of-band" value.

   Most attributes are defined to have a single attribute syntax.
   However, a few attributes (e.g., "job-sheet", "media", "job-hold-
   until") are defined to have several attribute syntaxes, depending on
   the value.  These multiple attribute syntaxes are separated by the
   "|" character in the sub-section heading to indicate the choice.
   Since each value MUST be tagged as to its attribute syntax in the
   protocol, a single-valued attribute instance may have any one of its
   attribute syntaxes and a multi-valued attribute instance may have a
   mixture of its defined attribute syntaxes.

4.1.1 'text'

   A text attribute is an attribute whose value is a sequence of zero or
   more characters encoded in a maximum of 1023 ('MAX') octets.  MAX is
   the maximum length for each value of any text attribute.  However, if
   an attribute will always contain values whose maximum length is much
   less than MAX, the definition of that attribute will include a
   qualifier that defines the maximum length for values of that
   attribute.  For example:  the "printer-location" attribute is
   specified as "printer-location (text(127))".  In this case, text
   values for "printer-location" MUST NOT exceed 127 octets; if supplied
   with a longer text string via some external interface (other than the
   protocol), implementations are free to truncate to this shorter
   length limitation.

   In this document, all text attributes are defined using the 'text'
   syntax.  However, 'text' is used only for brevity; the formal
   interpretation of 'text' is: 'textWithoutLanguage |
   textWithLanguage'.  That is, for any attribute defined in this
   document using the 'text' attribute syntax, all IPP objects and



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   clients MUST support both the 'textWithoutLanguage' and
   'textWithLanguage' attribute syntaxes.  However, in actual usage and
   protocol execution, objects and clients accept and return only one of
   the two syntax per attribute.  The syntax 'text' never appears "on-
   the-wire".

   Both 'textWithoutLanguage' and 'textWithLanguage' are needed to
   support the real world needs of interoperability between sites and
   systems that use different natural languages as the basis for human
   communication.  Generally, one natural language applies to all text
   attributes in a given request or response. The language is indicated
   by the "attributes-natural-language" operation attribute defined in
   section 3.1.4 or "attributes-natural-language" job attribute defined
   in section 4.3.20, and there is no need to identify the natural
   language for each text string on a value-by-value basis.  In these
   cases, the attribute syntax 'textWithoutLanguage' is used for text
   attributes.  In other cases, the client needs to supply or the
   Printer object needs to return a text value in a natural language
   that is different from the rest of the text values in the request or
   response.  In these cases, the client or Printer object uses the
   attribute syntax 'textWithLanguage' for text attributes (this is the
   Natural Language Override mechanism described in section 3.1.4).

   The 'textWithoutLanguage' and 'textWithLanguage' attribute syntaxes
   are described in more detail in the following sections.

4.1.1.1 'textWithoutLanguage'

   The 'textWithoutLanguage' syntax indicates a value that is sequence
   of zero or more characters encoded in a maximum of 1023 (MAX) octets.
   Text strings are encoded using the rules of some charset.  The
   Printer object MUST support the UTF-8 charset [RFC2279] and MAY
   support additional charsets to represent 'text' values, provided that
   the charsets are registered with IANA [IANA-CS].  See Section 4.1.7
   for the definition of the 'charset' attribute syntax, including
   restricted semantics and examples of charsets.

4.1.1.2 'textWithLanguage'

   The 'textWithLanguage' attribute syntax is a compound attribute
   syntax consisting of two parts: a 'textWithoutLanguage' part encoded
   in a maximum of 1023 (MAX) octets plus an additional
   'naturalLanguage' (see section 4.1.8) part that overrides the natural
   language in force.  The 'naturalLanguage' part explicitly identifies
   the natural language that applies to the text part of that value and
   that value alone.  For any give text attribute, the
   'textWithoutLanguage' part is limited to the maximum length defined
   for that 'text' attribute, and the 'naturalLanguage' part is always



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   limited to 63 (additional) octets.  Using the 'textWithLanguage'
   attribute syntax rather than the normal 'textWithoutLanguage' syntax
   is the so-called Natural Language Override mechanism and MUST be
   supported by all IPP objects and clients.

   If the attribute is multi-valued (1setOf text), then the
   'textWithLanguage' attribute syntax MUST be used to explicitly
   specify each attribute value whose natural language needs to be
   overridden.  Other values in a multi-valued 'text' attribute in a
   request or a response revert to the natural language of the operation
   attribute.

   In a create request, the Printer object MUST accept and store with
   the Job object any natural language in the "attributes-natural-
   language" operation attribute, whether the Printer object supports
   that natural language or not.  Furthermore, the Printer object MUST
   accept and store any 'textWithLanguage' attribute value, whether the
   Printer object supports that natural language or not.  These
   requirements are independent of the value of the "ipp-attribute-
   fidelity" operation attribute that the client MAY supply.

   Example:  If the client supplies the "attributes-natural-language"
   operation attribute with the value: 'en' indicating English, but the
   value of the "job-name" attribute is in French, the client MUST use
   the 'textWithLanguage' attribute syntax with the following two
   values:

      'fr': Natural Language Override indicating French
      'Rapport Mensuel': the job name in French

   See the "Encoding and Transport" document [RFC2910] section 3.9 for
   the encoding of the two parts and Appendix A for a detailed example
   of the 'textWithLanguage' attribute syntax.

4.1.2 'name'

   This syntax type is used for user-friendly strings, such as a Printer
   name, that, for humans, are more meaningful than identifiers.  Names
   are never translated from one natural language to another.  The
   'name' attribute syntax is essentially the same as 'text', including
   the REQUIRED support of UTF-8 except that the sequence of characters
   is limited so that its encoded form MUST NOT exceed 255 (MAX) octets.

   Also like 'text', 'name' is really an abbreviated notation for either
   'nameWithoutLanguage' or 'nameWithLanguage'.  That is, all IPP
   objects and clients MUST support both the 'nameWithoutLanguage' and
   'nameWithLanguage' attribute syntaxes.  However, in actual usage and




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   protocol execution, objects and clients accept and return only one of
   the two syntax per attribute.  The syntax 'name' never appears "on-
   the-wire".

   Only the 'text' and 'name' attribute syntaxes permit the Natural
   Language Override mechanism.

   Some attributes are defined as 'type3 keyword | name'.  These
   attributes support values that are either type3 keywords or names.
   This dual-syntax mechanism enables a site administrator to extend
   these attributes to legally include values that are locally defined
   by the site administrator.  Such names are not registered with IANA.

4.1.2.1 'nameWithoutLanguage'

   The 'nameWithoutLanguage' syntax indicates a value that is sequence
   of zero or more characters encoded in a maximum of 255 (MAX) octets.

4.1.2.2 'nameWithLanguage'

   The 'nameWithLanguage' attribute syntax is a compound attribute
   syntax consisting of two parts: a 'nameWithoutLanguage' part encoded
   in a maximum of 1023 (MAX) octets plus an additional
   'naturalLanguage' (see section 4.1.8) part that overrides the natural
   language in force.  The 'naturalLanguage' part explicitly identifies
   the natural language that applies to that name value and that name
   value alone.  For any give text attribute, the 'textWithoutLanguage'
   part is limited to the maximum length defined for that 'text'
   attribute, and the 'naturalLanguage' part is always limited to 63
   (additional) octets.  Using the 'textWithLanguage' attribute syntax
   rather than the normal 'textWithoutLanguage' syntax is the so-called
   Natural Language Override mechanism and MUST be supported by all IPP
   objects and clients.

   The 'nameWithLanguage' attribute syntax behaves the same as the
   'textWithLanguage' syntax.  Using the 'textWithLanguage' attribute
   syntax rather than the normal 'textWithoutLanguage' syntax is the
   so-called Natural Language Override mechanism and MUST be supported
   by all IPP objects and clients.  If a name is in a language that is
   different than the rest of the object or operation, then this
   'nameWithLanguage' syntax is used rather than the generic
   'nameWithoutLanguage' syntax.

   If the attribute is multi-valued (1setOf text), then the
   'nameWithLanguage' attribute syntax MUST be used to explicitly
   specify each attribute value whose natural language needs to be
   overridden.




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   Other values in a multi-valued 'name' attribute in a request or a
   response revert to the natural language of the operation attribute.

   In a create request, the Printer object MUST accept and store with
   the Job object any natural language in the "attributes-natural-
   language" operation attribute, whether the Printer object supports
   that natural language or not.  Furthermore, the Printer object MUST
   accept and store any 'nameWithLanguage' attribute value, whether the
   Printer object supports that natural language or not.  These
   requirements are independent of the value of the "ipp-attribute-
   fidelity" operation attribute that the client MAY supply.

   Example:  If the client supplies the "attributes-natural-language"
   operation attribute with the value:  'en' indicating English, but the
   "printer-name" attribute is in German, the client MUST use the
   'nameWithLanguage' attribute syntax as follows:

      'de':  Natural Language Override indicating German
      'Farbdrucker':  the Printer name in German

   See the "Encoding and Transport" document [RFC2910] section 3.9 for
   the encoding of the two parts and Appendix A for a detailed example
   of the 'nameWithLanguage' attribute syntax.

4.1.2.3 Matching 'name' attribute values

   For purposes of matching two 'name' attribute values for equality,
   such as in job validation (where a client-supplied value for
   attribute "xxx" is checked to see if the value is among the values of
   the Printer object's corresponding "xxx-supported" attribute), the
   following match rules apply:

      1. 'keyword' values never match 'name' values.

      2. 'name' (nameWithoutLanguage and nameWithLanguage) values match
         if (1) the name parts match and (2) the Associated Natural-
         Language parts (see section 3.1.4.1) match.  The matching rules
         are:

         a. the name parts match if the two names are identical
            character by character, except it is RECOMMENDED that case
            be ignored.  For example: 'Ajax-letter-head-white' MUST
            match 'Ajax-letter-head-white' and SHOULD match 'ajax-
            letter-head-white' and 'AJAX-LETTER-HEAD-WHITE'.







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         b. the Associated Natural-Language parts match if the shorter
            of the two meets the syntactic requirements of RFC 1766
            [RFC1766] and matches byte for byte with the longer.  For
            example, 'en' matches 'en', 'en-us' and 'en-gb', but matches
            neither 'fr' nor 'e'.

4.1.3 'keyword'

   The 'keyword' attribute syntax is a sequence of characters, length: 1
   to 255, containing only the US-ASCII [ASCII] encoded values for
   lowercase letters ("a" - "z"), digits ("0" - "9"), hyphen ("-"), dot
   ("."), and underscore ("_").  The first character MUST be a lowercase
   letter.  Furthermore, keywords MUST be in U.S. English.

   This syntax type is used for enumerating semantic identifiers of
   entities in the abstract protocol, i.e., entities identified in this
   document.  Keywords are used as attribute names or values of
   attributes.  Unlike 'text' and 'name' attribute values, 'keyword'
   values MUST NOT use the Natural Language Override mechanism, since
   they MUST always be US-ASCII and U.S. English.

   Keywords are for use in the protocol.  A user interface will likely
   provide a mapping between protocol keywords and displayable user-
   friendly words and phrases which are localized to the natural
   language of the user.  While the keywords specified in this document
   MAY be displayed to users whose natural language is U.S. English,
   they MAY be mapped to other U.S. English words for U.S. English
   users, since the user interface is outside the scope of this
   document.

   In the definition for each attribute of this syntax type, the full
   set of defined keyword values for that attribute are listed.

   When a keyword is used to represent an attribute (its name), it MUST
   be unique within the full scope of all IPP objects and attributes.
   When a keyword is used to represent a value of an attribute, it MUST
   be unique just within the scope of that attribute.  That is, the same
   keyword MUST NOT be used for two different values within the same
   attribute to mean two different semantic ideas.  However, the same
   keyword MAY be used across two or more attributes, representing
   different semantic ideas for each attribute.  Section 6.1 describes
   how the protocol can be extended with new keyword values.  Examples
   of attribute name keywords:

      "job-name"
      "attributes-charset"





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   Note:  This document uses "type1", "type2", and "type3" prefixes to
   the "keyword" basic syntax to indicate different levels of review for
   extensions (see section 6.1).

4.1.4 'enum'

   The 'enum' attribute syntax is an enumerated integer value that is in
   the range from 1 to 2**31 - 1 (MAX).   Each value has an associated
   'keyword' name.  In the definition for each attribute of this syntax
   type, the full set of possible values for that attribute are listed.
   This syntax type is used for attributes for which there are enum
   values assigned by other standards, such as SNMP MIBs.  A number of
   attribute enum values in this document are also used for
   corresponding attributes in other standards [RFC1759].  This syntax
   type is not used for attributes to which the administrator may assign
   values.  Section 6.1 describes how the protocol can be extended with
   new enum values.

   Enum values are for use in the protocol.  A user interface will
   provide a mapping between protocol enum values and displayable user-
   friendly words and phrases which are localized to the natural
   language of the user.  While the enum symbols specified in this
   document MAY be displayed to users whose natural language is U.S.
   English, they MAY be mapped to other U.S. English words for U.S.
   English users, since the user interface is outside the scope of this
   document.

   Note: SNMP MIBs use '2' for 'unknown' which corresponds to the IPP
   "out-of-band" value 'unknown'.  See the description of the "out-of-
   band" values at the beginning of Section 4.1.  Therefore, attributes
   of type 'enum' start at '3'.

   Note:  This document uses "type1", "type2", and "type3" prefixes to
   the "enum" basic syntax to indicate different levels of review for
   extensions (see section 6.1).

4.1.5 'uri'

   The 'uri' attribute syntax is any valid Uniform Resource Identifier
   or URI [RFC2396].  Most often, URIs are simply Uniform Resource
   Locators or URLs.  The maximum length of URIs used as values of IPP
   attributes is 1023 octets.  Although most other IPP attribute syntax
   types allow for only lower-cased values, this attribute syntax type
   conforms to the case-sensitive and case-insensitive rules specified
   in [RFC2396].  See also [IPP-IIG] for a discussion of case in URIs.






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4.1.6 'uriScheme'

   The 'uriScheme' attribute syntax is a sequence of characters
   representing a URI scheme according to RFC 2396 [RFC2396].  Though
   RFC 2396 requires that the values be case-insensitive, IPP requires
   all lower case values in IPP attributes to simplify comparing by IPP
   clients and Printer objects.

   Standard values for this syntax type are the following keywords:

      'ipp':  for IPP schemed URIs (e.g., "ipp:...")
      'http':  for HTTP schemed URIs (e.g., "http:...")
      'https':  for use with HTTPS schemed URIs (e.g., "https:...") (not
         on IETF standards track)
      'ftp': for FTP schemed URIs (e.g., "ftp:...")
      'mailto': for SMTP schemed URIs (e.g., "mailto:...")
      'file': for file schemed URIs (e.g., "file:...")

   A Printer object MAY support any URI 'scheme' that has been
   registered with IANA [IANA-MT]. The maximum length of URI 'scheme'
   values used to represent IPP attribute values is 63 octets.

4.1.7 'charset'

   The 'charset' attribute syntax is a standard identifier for a
   charset.  A charset is a coded character set and encoding scheme.
   Charsets are used for labeling certain document contents and 'text'
   and 'name' attribute values.  The syntax and semantics of this
   attribute syntax are specified in RFC 2046 [RFC2046] and contained in
   the IANA character-set Registry [IANA-CS] according to the IANA
   procedures [RFC2278].  Though RFC 2046 requires that the values be
   case-insensitive US-ASCII [ASCII], IPP requires all lower case values
   in IPP attributes to simplify comparing by IPP clients and Printer
   objects.  When a character-set in the IANA registry has more than one
   name (alias), the name labeled as "(preferred MIME name)", if
   present, MUST be used.

   The maximum length of 'charset' values used to represent IPP
   attribute values is 63 octets.

   Some examples are:

      'utf-8':  ISO 10646 Universal Multiple-Octet Coded Character Set
         (UCS) represented as the UTF-8 [RFC2279] transfer encoding
         scheme in which US-ASCII is a subset charset.
      'us-ascii':  7-bit American Standard Code for Information
         Interchange (ASCII), ANSI X3.4-1986 [ASCII].  That standard




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         defines US-ASCII, but RFC 2045 [RFC2045] eliminates most of the
         control characters from conformant usage in MIME and IPP.
      'iso-8859-1':  8-bit One-Byte Coded Character Set, Latin Alphabet
         Nr 1 [ISO8859-1].  That standard defines a coded character set
         that is used by Latin languages in the Western Hemisphere and
         Western Europe.  US-ASCII is a subset charset.

   Some attribute descriptions MAY place additional requirements on
   charset values that may be used, such as REQUIRED values that MUST be
   supported or additional restrictions, such as requiring that the
   charset have US- ASCII as a subset charset.

4.1.8 'naturalLanguage'

   The 'naturalLanguage' attribute syntax is a standard identifier for a
   natural language and optionally a country.  The values for this
   syntax type are defined by RFC 1766 [RFC1766].  Though RFC 1766
   requires that the values be case-insensitive US-ASCII [ASCII], IPP
   requires all lower case to simplify comparing by IPP clients and
   Printer objects.  Examples include:

      'en':  for English
      'en-us': for US English
      'fr': for French
      'de':  for German

   The maximum length of 'naturalLanguage' values used to represent IPP
   attribute values is 63 octets.

4.1.9 'mimeMediaType'

   The 'mimeMediaType' attribute syntax is the Internet Media Type
   (sometimes called MIME type) as defined by RFC 2046 [RFC2046] and
   registered according to the procedures of RFC 2048 [RFC2048] for
   identifying a document format.  The value MAY include a charset, or
   other, parameter, depending on the specification of the Media Type in
   the IANA Registry [IANA-MT].  Although most other IPP syntax types
   allow for only lower-cased values, this syntax type allows for
   mixed-case values which are case-insensitive.

   Examples are:
      'text/html': An HTML document
      'text/plain': A plain text document in US-ASCII (RFC 2046
         indicates that in the absence of the charset parameter MUST
         mean US-ASCII rather than simply unspecified) [RFC2046].
      'text/plain; charset=US-ASCII':  A plain text document in US-ASCII
         [52, 56].




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      'text/plain; charset=ISO-8859-1':  A plain text document in ISO
         8859-1 (Latin 1) [ISO8859-1].
      'text/plain; charset=utf-8':  A plain text document in ISO 10646
         represented as UTF-8 [RFC2279]
      'application/postscript':  A PostScript document [RFC2046]
      'application/vnd.hp-PCL':  A PCL document [IANA-MT] (charset
         escape sequence embedded in the document data)
      'application/pdf':  Portable Document Format - see IANA MIME Media
         Type registry
      'application/octet-stream': Auto-sense - see section 4.1.9.1

   The maximum length of a 'mimeMediaType' value to represent IPP
   attribute values is 255 octets.

4.1.9.1 Application/octet-stream -- Auto-Sensing the document format

   One special type is 'application/octet-stream'.  If the Printer
   object supports this value, the Printer object MUST be capable of
   auto-sensing the format of the document data using an
   implementation-dependent method that examines some number of octets
   of the document data, either as part of the create operation and/or
   at document processing time.  During auto-sensing, a Printer may
   determine that the document-data has a format that the Printer
   doesn't recognize.  If the Printer determines this problem before
   returning an operation response, it rejects the request and returns
   the 'client-error-document-format-not-supported' status code.  If the
   Printer determines this problem after accepting the request and
   returning an operation response with one of the successful status
   codes, the Printer adds the 'unsupported-document-format' value to
   the job's "job-state-reasons" attribute.

   If the Printer object's default value attribute "document-format-
   default" is set to 'application/octet-stream', the Printer object not
   only supports auto-sensing of the document format, but will depend on
   the result of applying its auto-sensing when the client does not
   supply the "document-format" attribute.  If the client supplies a
   document format value, the Printer MUST rely on the supplied
   attribute, rather than trust its auto-sensing algorithm.  To
   summarize:

      1. If the client does not supply a document format value, the
         Printer MUST rely on its default value setting (which may be
         'application/octet-stream' indicating an auto-sensing
         mechanism).
      2. If the client supplies a value other than 'application/octet-
         stream', the client is supplying valid information about the
         format of the document data and the Printer object MUST trust
         the client supplied value more than the outcome of applying an



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         automatic format detection mechanism.  For example, the client
         may be requesting the printing of a PostScript file as a
         'text/plain' document.  The Printer object MUST print a text
         representation of the PostScript commands rather than interpret
         the stream of PostScript commands and print the result.
      3. If the client supplies a value of 'application/octet-stream',
         the client is indicating that the Printer object MUST use its
         auto-sensing mechanism on the client supplied document data
         whether auto-sensing is the Printer object's default or not.

   Note:  Since the auto-sensing algorithm is probabilistic, if the
   client requests both auto-sensing ("document-format" set to
   'application/octet-stream') and true fidelity ("ipp-attribute-
   fidelity" set to 'true'), the Printer object might not be able to
   guarantee exactly what the end user intended (the auto-sensing
   algorithm might mistake one document format for another), but it is
   able to guarantee that its auto-sensing mechanism be used.

   When a Printer performs auto-sensing of a document in a submitted
   job, it is RECOMMENDED that the Printer indicate to the user that
   such auto-sensing has occurred and which document-format was auto-
   sensed by printing that information on the job's job-start-sheet.

4.1.10 'octetString'

   The 'octetString' attribute syntax is a sequence of octets encoded in
   a maximum of 1023 octets which is indicated in sub-section headers
   using the notation: octetString(MAX).  This syntax type is used for
   opaque data.

4.1.11 'boolean'

   The 'boolean' attribute syntax has only two values:  'true' and
   'false'.

4.1.12 'integer'

   The 'integer' attribute syntax is an integer value that is in the
   range from -2**31 (MIN) to 2**31 - 1 (MAX).  Each individual
   attribute may specify the range constraint explicitly in sub-section
   headers if the range is different from the full range of possible
   integer values.  For example:  job-priority (integer(1:100)) for the
   "job-priority" attribute.  However, the enforcement of that
   additional constraint is up to the IPP objects, not the protocol.







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4.1.13 'rangeOfInteger'

   The 'rangeOfInteger' attribute syntax is an ordered pair of integers
   that defines an inclusive range of integer values.  The first integer
   specifies the lower bound and the second specifies the upper bound.
   If a range constraint is specified in the header description for an
   attribute in this document whose attribute syntax is 'rangeOfInteger'
   (i.e., 'X:Y' indicating X as a minimum value and Y as a maximum
   value), then the constraint applies to both integers.

4.1.14 'dateTime'

   The 'dateTime' attribute syntax is a standard, fixed length, 11 octet
   representation of the "DateAndTime" syntax as defined in RFC 2579
   [RFC2579].  RFC 2579 also identifies an 8 octet representation of a
   "DateAndTime" value, but IPP objects MUST use the 11 octet
   representation.  A user interface will provide a mapping between
   protocol dateTime values and displayable user-friendly words or
   presentation values and phrases which are localized to the natural
   language and date format of the user, including time zone.

4.1.15 'resolution'

   The 'resolution' attribute syntax specifies a two-dimensional
   resolution in the indicated units.  It consists of 3 values: a cross
   feed direction resolution (positive integer value), a feed direction
   resolution (positive integer value), and a units value.  The
   semantics of these three components are taken from the Printer MIB
   [RFC1759] suggested values.  That is, the cross feed direction
   component resolution component is the same as the
   prtMarkerAddressabilityXFeedDir object in the Printer MIB, the feed
   direction component resolution component is the same as the
   prtMarkerAddressabilityFeedDir in the Printer MIB, and the units
   component is the same as the prtMarkerAddressabilityUnit object in
   the Printer MIB (namely, '3' indicates dots per inch and '4'
   indicates dots per centimeter).  All three values MUST be present
   even if the first two values are the same.  Example:  '300', '600',
   '3' indicates a 300 dpi cross-feed direction resolution, a 600 dpi
   feed direction resolution, since a '3' indicates dots per inch (dpi).

4.1.16 '1setOf  X'

   The '1setOf  X' attribute syntax is 1 or more values of attribute
   syntax type X.  This syntax type is used for multi-valued attributes.
   The syntax type is called '1setOf' rather than just 'setOf' as a
   reminder that the set of values MUST NOT be empty (i.e., a set of





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   size 0).  Sets are normally unordered.  However each attribute
   description of this type may specify that the values MUST be in a
   certain order for that attribute.

4.2 Job Template Attributes

   Job Template attributes describe job processing behavior.  Support
   for Job Template attributes by a Printer object is OPTIONAL (see
   section 12.2.3 for a description of support for OPTIONAL attributes).
   Also, clients OPTIONALLY supply Job Template attributes in create
   requests.

   Job Template attributes conform to the following rules.  For each Job
   Template attribute called "xxx":

      1. If the Printer object supports "xxx" then it MUST support both
         a "xxx-default" attribute (unless there is a "No" in the table
         below) and a "xxx-supported" attribute.  If the Printer object
         doesn't support "xxx", then it MUST support neither an "xxx-
         default" attribute nor an "xxx-supported" attribute, and it
         MUST treat an attribute "xxx" supplied by a client as
         unsupported.  An attribute "xxx" may be supported for some
         document formats and not supported for other document formats.
         For example, it is expected that a Printer object would only
         support "orientation-requested" for some document formats (such
         as 'text/plain' or 'text/html') but not others (such as
         'application/postscript').

      2. "xxx" is OPTIONALLY supplied by the client in a create request.
         If "xxx" is supplied, the client is indicating a desired job
         processing behavior for this Job.  When "xxx" is not supplied,
         the client is indicating that the Printer object apply its
         default job processing behavior at job processing time if the
         document content does not contain an embedded instruction
         indicating an xxx-related behavior.

         Since an administrator MAY change the default value attribute
         after a Job object has been submitted but before it has been
         processed, the default value used by the Printer object at job
         processing time may be different that the default value in
         effect at job submission time.

      3. The "xxx-supported" attribute is a Printer object attribute
         that describes which job processing behaviors are supported by
         that Printer object.  A client can query the Printer object to
         find out what xxx-related behaviors are supported by inspecting
         the returned values of the "xxx-supported" attribute.




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         Note: The "xxx" in each "xxx-supported" attribute name is
         singular, even though an "xxx-supported" attribute usually has
         more than one value, such as "job-sheet-supported", unless the
         "xxx" Job Template attribute is plural, such as "finishings" or
         "sides".  In such cases the "xxx-supported" attribute names
         are: "finishings- supported" and "sides-supported".

      4. The "xxx-default" default value attribute describes what will
         be done at job processing time when no other job processing
         information is supplied by the client (either explicitly as an
         IPP attribute in the create request or implicitly as an
         embedded instruction within the document data).

   If an application wishes to present an end user with a list of
   supported values from which to choose, the application SHOULD query
   the Printer object for its supported value attributes.  The
   application SHOULD also query the default value attributes.  If the
   application then limits selectable values to only those value that
   are supported, the application can guarantee that the values supplied
   by the client in the create request all fall within the set of
   supported values at the Printer.  When querying the Printer, the
   client MAY enumerate each attribute by name in the Get-Printer-
   Attributes Request, or the client MAY just name the "job-template"
   group in order to get the complete set of supported attributes (both
   supported and default attributes).

   The "finishings" attribute is an example of a Job Template attribute.
   It can take on a set of values such as 'staple', 'punch', and/or
   'cover'.  A client can query the Printer object for the "finishings-
   supported" attribute and the "finishings-default" attribute.  The
   supported attribute contains a set of supported values.  The default
   value attribute contains the finishing value(s) that will be used for
   a new Job if the client does not supply a "finishings" attribute in
   the create request and the document data does not contain any
   corresponding finishing instructions.  If the client does supply the
   "finishings" attribute in the create request, the IPP object
   validates the value or values to make sure that they are a subset of
   the supported values identified in the Printer object's "finishings-
   supported" attribute.  See section 3.1.7.

   The table below summarizes the names and relationships for all Job
   Template attributes. The first column of the table (labeled "Job
   Attribute") shows the name and syntax for each Job Template attribute
   in the Job object. These are the attributes that can optionally be
   supplied by the client in a create request.   The last two columns
   (labeled "Printer: Default Value Attribute" and "Printer: Supported
   Values Attribute") show the name and syntax for each Job Template
   attribute in the Printer object (the default value attribute and the



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   supported values attribute).  A "No" in the table means the Printer
   MUST NOT support the attribute (that is, the attribute is simply not
   applicable).  For brevity in the table, the 'text' and 'name' entries
   do not show the maximum length for each attribute.

     +===================+======================+======================+
     | Job Attribute     |Printer: Default Value|  Printer: Supported  |
     |                   |   Attribute          |   Values Attribute   |
     +===================+======================+======================+
     | job-priority      | job-priority-default |job-priority-supported|
     | (integer 1:100)   | (integer 1:100)      |(integer 1:100)       |
     +-------------------+----------------------+----------------------+
     | job-hold-until    | job-hold-until-      |job-hold-until-       |
     | (type3 keyword |  |  default             | supported            |
     |    name)          |  (type3 keyword |    |(1setOf (             |
     |                   |    name)             |type3 keyword | name))|
     +-------------------+----------------------+----------------------+
     | job-sheets        | job-sheets-default   |job-sheets-supported  |
     | (type3 keyword |  | (type3 keyword |     |(1setOf (             |
     |    name)          |    name)             |type3 keyword | name))|
     +-------------------+----------------------+----------------------+
     |multiple-document- |multiple-document-    |multiple-document-    |
     | handling          | handling-default     |handling-supported    |
     | (type2 keyword)   | (type2 keyword)      |(1setOf type2 keyword)|
     +-------------------+----------------------+----------------------+
     | copies            | copies-default       | copies-supported     |
     | (integer (1:MAX)) | (integer (1:MAX))    | (rangeOfInteger      |
     |                   |                      |       (1:MAX))       |
     +-------------------+----------------------+----------------------+
     | finishings        | finishings-default   | finishings-supported |
     |(1setOf type2 enum)|(1setOf type2 enum)   |(1setOf type2 enum)   |
     +-------------------+----------------------+----------------------+
     | page-ranges       | No                   | page-ranges-         |
     | (1setOf           |                      | supported (boolean)  |
     |   rangeOfInteger  |                      |                      |
     |        (1:MAX))   |                      |                      |
     +-------------------+----------------------+----------------------+
     | sides             | sides-default        | sides-supported      |
     | (type2 keyword)   | (type2 keyword)      |(1setOf type2 keyword)|
     +-------------------+----------------------+----------------------+
     | number-up         | number-up-default    | number-up-supported  |
     | (integer (1:MAX)) | (integer (1:MAX))    |(1setOf (integer      |
     |                   |                      | (1:MAX) |            |
     |                   |                      |  rangeOfInteger      |
     |                   |                      |   (1:MAX)))          |






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     +-------------------+----------------------+----------------------+
     | orientation-      |orientation-requested-|orientation-requested-|
     |  requested        |  default             |  supported           |
     |   (type2 enum)    |  (type2 enum)        |  (1setOf type2 enum) |
     +-------------------+----------------------+----------------------+
     | media             | media-default        | media-supported      |
     | (type3 keyword |  | (type3 keyword |     |(1setOf (             |
     |    name)          |    name)             |type3 keyword | name))|
     |                   |                      |                      |
     |                   |                      | media-ready          |
     |                   |                      |(1setOf (             |
     |                   |                      |type3 keyword | name))|
     +-------------------+----------------------+----------------------+
     | printer-resolution| printer-resolution-  | printer-resolution-  |
     | (resolution)      |  default             | supported            |
     |                   | (resolution)         |(1setOf resolution)   |
     +-------------------+----------------------+----------------------+
     | print-quality     | print-quality-default| print-quality-       |
     | (type2 enum)      | (type2 enum)         | supported            |
     |                   |                      |(1setOf type2 enum)   |
     +-------------------+----------------------+----------------------+

4.2.1 job-priority (integer(1:100))

   This attribute specifies a priority for scheduling the Job. A higher
   value specifies a higher priority. The value 1 indicates the lowest
   possible priority. The value 100 indicates the highest possible
   priority.  Among those jobs that are ready to print, a Printer MUST
   print all jobs with a priority value of n before printing those with
   a priority value of n-1 for all n.

   If the Printer object supports this attribute, it MUST always support
   the full range from 1 to 100.  No administrative restrictions are
   permitted.  This way an end-user can always make full use of the
   entire range with any Printer object.  If privileged jobs are
   implemented outside IPP/1.1, they MUST have priorities higher than
   100, rather than restricting the range available to end-users.

   If the client does not supply this attribute and this attribute is
   supported by the Printer object, the Printer object MUST use the
   value of the Printer object's "job-priority-default" at job
   submission time (unlike most Job Template attributes that are used if
   necessary at job processing time).

   The syntax for the "job-priority-supported" is also integer(1:100).
   This single integer value indicates the number of priority levels
   supported.  The Printer object MUST take the value supplied by the
   client and map it to the closest integer in a sequence of n integers



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   values that are evenly distributed over the range from 1 to 100 using
   the formula:

      roundToNearestInt((100x+50)/n)

   where n is the value of "job-priority-supported" and x ranges from 0
   through n-1.

   For example, if n=1 the sequence of values is 50;  if n=2, the
   sequence of values is:  25 and 75;  if n = 3, the sequence of values
   is:  17, 50 and 83;  if n = 10, the sequence of values is: 5, 15, 25,
   35, 45, 55, 65, 75, 85, and 95;  if n = 100, the sequence of values
   is:  1, 2, 3, ... 100.

   If the value of the Printer object's "job-priority-supported" is 10
   and the client supplies values in the range 1 to 10, the Printer
   object maps them to 5, in the range 11 to 20, the Printer object maps
   them to 15, etc.

4.2.2 job-hold-until (type3 keyword | name (MAX))

   This attribute specifies the named time period during which the Job
   MUST become a candidate for printing.

   Standard keyword values for named time periods are:

      'no-hold': immediately, if there are not other reasons to hold the
         job
      'indefinite':  - the job is held indefinitely, until a client
         performs a Release-Job (section 3.3.6)
      'day-time': during the day
      'evening': evening
      'night': night
      'weekend': weekend
      'second-shift': second-shift (after close of business)
      'third-shift': third-shift (after midnight)

   An administrator MUST associate allowable print times with a named
   time period (by means outside the scope of this IPP/1.1 document).
   An administrator is encouraged to pick names that suggest the type of
   time period. An administrator MAY define additional values using the
   'name' or 'keyword' attribute syntax, depending on implementation.

   If the value of this attribute specifies a time period that is in the
   future, the Printer SHOULD add the 'job-hold-until-specified' value
   to the job's "job-state-reasons" attribute, MUST move the job to the





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   'pending-held' state, and MUST NOT schedule the job for printing
   until the specified time-period arrives.

   When the specified time period arrives, the Printer MUST remove the
   'job-hold-until-specified' value from the job's "job-state-reason"
   attribute, if present.  If there are no other job state reasons that
   keep the job in the 'pending-held' state, the Printer MUST consider
   the job as a candidate for processing by moving the job to the
   'pending' state.

   If this job attribute value is the named value 'no-hold', or the
   specified time period has already started, the job MUST be a
   candidate for processing immediately.

   If the client does not supply this attribute and this attribute is
   supported by the Printer object, the Printer object MUST use the
   value of the Printer object's "job-hold-until-default" at job
   submission time (unlike most Job Template attributes that are used if
   necessary at job processing time).

4.2.3 job-sheets (type3 keyword | name(MAX))

   This attribute determines which job start/end sheet(s), if any, MUST
   be printed with a job.

   Standard keyword values are:

      'none': no job sheet is printed
      'standard': one or more site specific standard job sheets are
         printed, e.g. a single start sheet or both start and end sheet is
         printed

   An administrator MAY define additional values using the 'name' or
   'keyword' attribute syntax, depending on implementation.

   The effect of this attribute on jobs with multiple documents MAY be
   affected by the "multiple-document-handling" job attribute (section
   4.2.4), depending on the job sheet semantics.

4.2.4 multiple-document-handling (type2 keyword)

   This attribute is relevant only if a job consists of two or more
   documents. This attribute MUST be supported with at least one value
   if the Printer supports multiple documents per job (see sections
   3.2.4 and 3.3.1).  The attribute controls finishing operations and
   the placement of one or more print-stream pages into impressions and
   onto media sheets.  When the value of the "copies" attribute exceeds
   1, it also controls the order in which the copies that result from



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   processing the documents are produced. For the purposes of this
   explanations, if "a" represents an instance of document data, then
   the result of processing the data in document "a" is a sequence of
   media sheets represented by "a(*)".

   Standard keyword values are:

      'single-document': If a Job object has multiple documents, say,
         the document data is called a and b, then the result of
         processing all the document data (a and then b) MUST be treated
         as a single sequence of media sheets for finishing operations;
         that is, finishing would be performed on the concatenation of
         the sequences a(*),b(*).  The Printer object MUST NOT force the
         data in each document instance to be formatted onto a new
         print-stream page, nor to start a new impression on a new media
         sheet. If more than one copy is made, the ordering of the sets
         of media sheets resulting from processing the document data
         MUST be a(*), b(*), a(*), b(*), start on a new media sheet.
      'separate-documents-uncollated-copies': If a Job object has
         multiple documents, say, the document data is called a and b,
         then the result of processing the data in each document
         instance MUST be treated as a single sequence of media sheets
         for finishing operations; that is, the sets a(*) and b(*) would
         each be finished separately. The Printer object MUST force each
         copy of the result of processing the data in a single document
         to start on a new media sheet. If more than one copy is made,
         the ordering of the sets of media sheets resulting from
         processing the document data MUST be a(*), a(*), ..., b(*),
         b(*) ... .
      'separate-documents-collated-copies': If a Job object has multiple
         documents, say, the document data is called a and b, then the
         result of processing the data in each document instance MUST be
         treated as a single sequence of media sheets for finishing
         operations; that is, the sets a(*) and b(*) would each be
         finished separately. The Printer object MUST force each copy of
         the result of processing the data in a single document to start
         on a new media sheet.  If more than one copy is made, the
         ordering of the sets of media sheets resulting from processing
         the document data MUST be a(*), b(*), a(*), b(*), ... .
      'single-document-new-sheet':  Same as 'single-document', except
         that the Printer object MUST ensure that the first impression
         of each document instance in the job is placed on a new media
         sheet.  This value allows multiple documents to be stapled
         together with a single staple where each document starts on a
         new sheet.






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   The 'single-document' value is the same as 'separate-documents-
   collated-copies' with respect to ordering of print-stream pages, but
   not media sheet generation, since 'single-document' will put the
   first page of the next document on the back side of a sheet if an odd
   number of pages have been produced so far for the job, while
   'separate-documents-collated- copies' always forces the next document
   or document copy on to a new sheet.  In addition, if the "finishings"
   attribute specifies 'staple', then with 'single-document', documents
   a and b are stapled together as a single document with no regard to
   new sheets, with 'single-document-new-sheet', documents a and b are
   stapled together as a single document, but document b starts on a new
   sheet, but with 'separate-documents-uncollated-copies' and
   'separate-documents-collated-copies', documents a and b are stapled
   separately.

   Note: None of these values provide means to produce uncollated sheets
   within a document, i.e., where multiple copies of sheet n are
   produced before sheet n+1 of the same document.

   The relationship of this attribute and the other attributes that
   control document processing is described in section 15.3.

4.2.5 copies (integer(1:MAX))

   This attribute specifies the number of copies to be printed.

   On many devices the supported number of collated copies will be
   limited by the number of physical output bins on the device, and may
   be different from the number of uncollated copies which can be
   supported.

   Note: The effect of this attribute on jobs with multiple documents is
   controlled by the "multiple-document-handling" job attribute (section
   4.2.4) and the relationship of this attribute and the other
   attributes that control document processing is described in section
   15.3.

4.2.6 finishings (1setOf type2 enum)

   This attribute identifies the finishing operations that the Printer
   uses for each copy of each printed document in the Job. For Jobs with
   multiple documents, the "multiple-document-handling" attribute
   determines what constitutes a "copy" for purposes of finishing.








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   Standard enum values are:

   Value  Symbolic Name and Description

   '3'    'none':  Perform no finishing
   '4'    'staple':  Bind the document(s) with one or more staples. The
             exact number and placement of the staples is site-
             defined.
   '5'    'punch':  This value indicates that holes are required in the
             finished document. The exact number and placement of the
             holes is site-defined  The punch specification MAY be
             satisfied (in a site- and implementation-specific manner)
             either by drilling/punching, or by substituting pre-
             drilled media.
   '6'    'cover':  This value is specified when it is desired to select
             a non-printed (or pre-printed) cover for the document.
             This does not supplant the specification of a printed
             cover (on cover stock medium) by the document itself.
   '7'    'bind':  This value indicates that a binding is to be applied
             to the document; the type and placement of the binding is
             site-defined.
   '8'    'saddle-stitch':  Bind the document(s) with one or more
             staples (wire stitches) along the middle fold.  The exact
             number and placement of the staples and the middle fold
             is implementation and/or site-defined.
   '9'    'edge-stitch':  Bind the document(s) with one or more staples
             (wire stitches) along one edge.  The exact number and
             placement of the staples is implementation and/or site-
             defined.
   '10'-'19'   reserved for future generic finishing enum values.

   The following values are more specific; they indicate a corner or an
   edge as if the document were a portrait document (see below):

   '20'   'staple-top-left':  Bind the document(s) with one or more
             staples in the top left corner.
   '21'   'staple-bottom-left':  Bind the document(s) with one or more
             staples in the bottom left corner.
   '22'   'staple-top-right':  Bind the document(s) with one or more
             staples in the top right corner.
   '23'   'staple-bottom-right':  Bind the document(s) with one or more
             staples in the bottom right corner.
   '24'   'edge-stitch-left':  Bind the document(s) with one or more
             staples (wire stitches) along the left edge.  The exact
             number and placement of the staples is implementation
             and/or site-defined.





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   '25'   'edge-stitch-top':  Bind the document(s) with one or more
             staples (wire stitches) along the top edge.  The exact
             number and placement of the staples is implementation
             and/or site-defined.
   '26'   'edge-stitch-right':  Bind the document(s) with one or more
             staples (wire stitches) along the right edge.  The exact
             number and placement of the staples is implementation
             and/or site-defined.
   '27'   'edge-stitch-bottom':  Bind the document(s) with one or more
             staples (wire stitches) along the bottom edge.  The exact
             number and placement of the staples is implementation
             and/or site-defined.
   '28'   'staple-dual-left':  Bind the document(s) with two staples
             (wire stitches) along the left edge assuming a portrait
             document (see above).
   '29'   'staple-dual-top':  Bind the document(s) with two staples
             (wire stitches) along the top edge assuming a portrait
             document (see above).
   '30'   'staple-dual-right':  Bind the document(s) with two staples
             (wire stitches) along the right edge assuming a portrait
             document (see above).
   '31'   'staple-dual-bottom':  Bind the document(s) with two staples
             (wire stitches) along the bottom edge assuming a portrait
             document (see above).

   The 'staple-xxx' values are specified with respect to the document as
   if the document were a portrait document.  If the document is
   actually a landscape or a reverse-landscape document, the client
   supplies the appropriate transformed value.  For example, to position
   a staple in the upper left hand corner of a landscape document when
   held for reading, the client supplies the 'staple-bottom-left' value
   (since landscape is defined as a +90 degree rotation of the image
   with respect to the media from portrait, i.e., anti-clockwise).  On
   the other hand, to position a staple in the upper left hand corner of
   a reverse-landscape document when held for reading, the client
   supplies the 'staple-top-right' value (since reverse-landscape is
   defined as a -90 degree rotation of the image with respect to the
   media from portrait, i.e., clockwise).

   The angle (vertical, horizontal, angled) of each staple with respect
   to the document depends on the implementation which may in turn
   depend on the value of the attribute.

   Note: The effect of this attribute on jobs with multiple documents is
   controlled by the "multiple-document-handling" job attribute (section
   4.2.4) and the relationship of this attribute and the other
   attributes that control document processing is described in section
   15.3.



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   If the client supplies a value of 'none' along with any other
   combination of values, it is the same as if only that other
   combination of values had been supplied (that is the 'none' value has
   no effect).

4.2.7 page-ranges (1setOf rangeOfInteger (1:MAX))

   This attribute identifies the range(s) of print-stream pages that the
   Printer object uses for each copy of each document which are to be
   printed.  Nothing is printed for any pages identified that do not
   exist in the document(s).  Ranges MUST be in ascending order, for
   example: 1-3, 5-7, 15-19 and MUST NOT overlap, so that a non-spooling
   Printer object can process the job in a single pass.  If the ranges
   are not ascending or are overlapping, the IPP object MUST reject the
   request and return the 'client-error-bad-request' status code.  The
   attribute is associated with print-stream pages not application-
   numbered pages (for example, the page numbers found in the headers
   and or footers for certain word processing applications).

   For Jobs with multiple documents, the "multiple-document-handling"
   attribute determines what constitutes a "copy" for purposes of the
   specified page range(s).  When "multiple-document-handling" is
   'single-document', the Printer object MUST apply each supplied page
   range once to the concatenation of the print-stream pages.  For
   example, if there are 8 documents of 10 pages each, the page-range
   '41:60' prints the pages in the 5th and 6th documents as a single
   document and none of the pages of the other documents are printed.
   When "multiple-document- handling" is 'separate-documents-
   uncollated-copies' or 'separate-documents-collated-copies', the
   Printer object MUST apply each supplied page range repeatedly to each
   document copy.  For the same job, the page-range '1:3, 10:10' would
   print the first 3 pages and the 10th page of each of the 8 documents
   in the Job, as 8 separate documents.

   In most cases, the exact pages to be printed will be generated by a
   device driver and this attribute would not be required.  However,
   when printing an archived document which has already been formatted,
   the end user may elect to print just a subset of the pages contained
   in the document.  In this case, if page-range = n.m is specified, the
   first page to be printed will be page n. All subsequent pages of the
   document will be printed through and including page m.

   "page-ranges-supported" is a boolean value indicating whether or not
   the printer is capable of supporting the printing of page ranges.
   This capability may differ from one PDL to another. There is no
   "page-ranges-default" attribute.  If the "page-ranges" attribute is
   not supplied by the client, all pages of the document will be
   printed.



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   Note: The effect of this attribute on jobs with multiple documents is
   controlled by the "multiple-document-handling" job attribute (section
   4.2.4) and the relationship of this attribute and the other
   attributes that control document processing is described in section
   15.3.

4.2.8 sides (type2 keyword)

   This attribute specifies how print-stream pages are to be imposed
   upon the sides of an instance of a selected medium, i.e., an
   impression.

   The standard keyword values are:

      'one-sided': imposes each consecutive print-stream page upon the
         same side of consecutive media sheets.
      'two-sided-long-edge': imposes each consecutive pair of print-
         stream pages upon front and back sides of consecutive media
         sheets, such that the orientation of each pair of print-stream
         pages on the medium would be correct for the reader as if for
         binding on the long edge.  This imposition is sometimes called
         'duplex' or 'head-to-head'.
      'two-sided-short-edge': imposes each consecutive pair of print-
         stream pages upon front and back sides of consecutive media
         sheets, such that the orientation of each pair of print-stream
         pages on the medium would be correct for the reader as if for
         binding on the short edge.  This imposition is sometimes called
         'tumble' or 'head-to-toe'.
      'two-sided-long-edge', 'two-sided-short-edge',
         'tumble', and 'duplex' all work the same for portrait or
         landscape.  However
         'head-to-toe' is
      'tumble' in portrait but 'duplex' in landscape.  'head-to-head'
         also switches between 'duplex' and 'tumble' when using portrait
         and landscape modes.

   Note: The effect of this attribute on jobs with multiple documents is
   controlled by the "multiple-document-handling" job attribute (section
   4.2.4) and the relationship of this attribute and the other
   attributes that control document processing is described in section
   15.3.

4.2.9 number-up (integer(1:MAX))

   This attribute specifies the number of print-stream pages to impose
   upon a single side of an instance of a selected medium.  For example,
   if the value is:




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   Value  Description

   '1'    the Printer MUST place one print-stream page on a single side
             of an instance of the selected medium (MAY add some sort
             of translation, scaling, or rotation).
   '2'    the Printer MUST place two print-stream pages on a single side
             of an instance of the selected medium (MAY add some sort
             of translation, scaling, or rotation).
   '4'    the Printer MUST place four print-stream pages on a single
             side of an instance of the selected medium (MAY add some
             sort of translation, scaling, or rotation).

   This attribute primarily controls the translation, scaling and
   rotation of print-stream pages.

   Note: The effect of this attribute on jobs with multiple documents is
   controlled by the "multiple-document-handling" job attribute (section
   4.2.4) and the relationship of this attribute and the other
   attributes that control document processing is described in section
   15.3.

4.2.10 orientation-requested (type2 enum)

   This attribute indicates the desired orientation for printed print-
   stream pages; it does not describe the orientation of the client-
   supplied print-stream pages.

   For some document formats (such as 'application/postscript'), the
   desired orientation of the print-stream pages is specified within the
   document data.  This information is generated by a device driver
   prior to the submission of the print job.  Other document formats
   (such as 'text/plain') do not include the notion of desired
   orientation within the document data.  In the latter case it is
   possible for the Printer object to bind the desired orientation to
   the document data after it has been submitted.  It is expected that a
   Printer object would only support "orientations-requested" for some
   document formats (e.g., 'text/plain' or 'text/html') but not others
   (e.g., 'application/postscript').  This is no different than any
   other Job Template attribute since section 4.2, item 1, points out
   that a Printer object may support or not support any Job Template
   attribute based on the document format supplied by the client.
   However, a special mention is made here since it is very likely that
   a Printer object will support "orientation-requested" for only a
   subset of the supported document formats.







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   Standard enum values are:

   Value  Symbolic Name and Description

   '3'    'portrait':  The content will be imaged across the short edge
             of the medium.
   '4'    'landscape':  The content will be imaged across the long edge
             of the medium.  Landscape is defined to be a rotation of
             the print-stream page to be imaged by +90 degrees with
             respect to the medium (i.e. anti-clockwise) from the
             portrait orientation.  Note:  The +90 direction was
             chosen because simple finishing on the long edge is the
             same edge whether portrait or landscape
   '5'    'reverse-landscape':  The content will be imaged across the
             long edge of the medium.  Reverse-landscape is defined to
             be a rotation of the print-stream page to be imaged by -
             90 degrees with respect to the medium (i.e. clockwise)
             from the portrait orientation.  Note: The 'reverse-
             landscape' value was added because some applications
             rotate landscape -90 degrees from portrait, rather than
             +90 degrees.
   '6'    'reverse-portrait':  The content will be imaged across the
             short edge of the medium.  Reverse-portrait is defined to
             be a rotation of the print-stream page to be imaged by
             180 degrees with respect to the medium from the portrait
             orientation.  Note: The 'reverse-portrait' value was
             added for use with the "finishings" attribute in cases
             where the opposite edge is desired for finishing a
             portrait document on simple finishing devices that have
             only one finishing position.  Thus a 'text'/plain'
             portrait document can be stapled "on the right" by a
             simple finishing device as is common use with some middle
             eastern languages such as Hebrew.

   Note: The effect of this attribute on jobs with multiple documents is
   controlled by the "multiple-document-handling" job attribute (section
   4.2.4) and the relationship of this attribute and the other
   attributes that control document processing is described in section
   15.3.

4.2.11 media (type3 keyword | name(MAX))

   This attribute identifies the medium that the Printer uses for all
   impressions of the Job.

   The values for "media" include medium-names, medium-sizes, input-
   trays and electronic forms so that one attribute specifies the media.
   If a Printer object supports a medium name as a value of this



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   attribute, such a medium name implicitly selects an input-tray that
   contains the specified medium.  If a Printer object supports a medium
   size as a value of this attribute, such a medium size implicitly
   selects a medium name that in turn implicitly selects an input-tray
   that contains the medium with the specified size.  If a Printer
   object supports an input-tray as the value of this attribute, such an
   input-tray implicitly selects the medium that is in that input-tray
   at the time the job prints.  This case includes manual-feed input-
   trays.  If a Printer object supports an electronic form as the value
   of this attribute, such an electronic form implicitly selects a
   medium-name that in turn implicitly selects an input-tray that
   contains the medium specified by the electronic form.  The electronic
   form also implicitly selects an image that the Printer MUST merge
   with the document data as its prints each page.

   Standard keyword values are taken from ISO DPA [ISO10175], the
   Printer MIB [RFC1759], and ASME-Y14.1M [ASME-Y14.1M] and are listed
   in section 14.  An administrator MAY define additional values using
   the 'name' or 'keyword' attribute syntax, depending on
   implementation.

   There is also an additional Printer attribute named "media-ready"
   which differs from "media-supported" in that legal values only
   include the subset of "media-supported" values that are physically
   loaded and ready for printing with no operator intervention required.
   If an IPP object supports "media-supported", it NEED NOT support
   "media-ready".

   The relationship of this attribute and the other attributes that
   control document processing is described in section 15.3.

4.2.12 printer-resolution (resolution)

   This attribute identifies the resolution that Printer uses for the
   Job.

4.2.13 print-quality (type2 enum)

   This attribute specifies the print quality that the Printer uses for
   the Job.

   The standard enum values are:

   Value  Symbolic Name and Description

   '3'    'draft': lowest quality available on the printer
   '4'    'normal': normal or intermediate quality on the printer
   '5'    'high': highest quality available on the printer



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4.3 Job Description Attributes

   The attributes in this section form the attribute group called "job-
   description".  The following table summarizes these attributes.  The
   third column indicates whether the attribute is a REQUIRED attribute
   that MUST be supported by Printer objects.  If it is not indicated as
   REQUIRED, then it is OPTIONAL.  The maximum size in octets for 'text'
   and 'name' attributes is indicated in parenthesizes.

   +----------------------------+----------------------+--------------+
   |      Attribute             |     Syntax           |   REQUIRED?  |
   +----------------------------+----------------------+--------------+
   | job-uri                    | uri                  |  REQUIRED    |
   +----------------------------+----------------------+--------------+
   | job-id                     | integer(1:MAX)       |  REQUIRED    |
   +----------------------------+----------------------+--------------+
   | job-printer-uri            | uri                  |  REQUIRED    |
   +----------------------------+----------------------+--------------+
   | job-more-info              | uri                  |              |
   +----------------------------+----------------------+--------------+
   | job-name                   | name (MAX)           |  REQUIRED    |
   +----------------------------+----------------------+--------------+
   | job-originating-user-name  | name (MAX)           |  REQUIRED    |
   +----------------------------+----------------------+--------------+
   | job-state                  | type1 enum           |  REQUIRED    |
   +----------------------------+----------------------+--------------+
   | job-state-reasons          | 1setOf type2 keyword |  REQUIRED    |
   +----------------------------+----------------------+--------------+
   | job-state-message          | text (MAX)           |              |
   +----------------------------+----------------------+--------------+
   | job-detailed-status-       | 1setOf text (MAX)    |              |
   |       messages             |                      |              |
   +----------------------------+----------------------+--------------+
   | job-document-access-errors | 1setOf text (MAX)    |              |
   +----------------------------+----------------------+--------------+
   | number-of-documents        | integer (0:MAX)      |              |
   +----------------------------+----------------------+--------------+
   | output-device-assigned     | name (127)           |              |
   +----------------------------+----------------------+--------------+
   | time-at-creation           | integer (MIN:MAX)    |  REQUIRED    |
   +----------------------------+----------------------+--------------+
   | time-at-processing         | integer (MIN:MAX)    |  REQUIRED    |
   +----------------------------+----------------------+--------------+
   | time-at-completed          | integer (MIN:MAX)    |  REQUIRED    |
   +----------------------------+----------------------+--------------+
   | job-printer-up-time        | integer (1:MAX)      |  REQUIRED    |
   +----------------------------+----------------------+--------------+
   | date-time-at-creation      | dateTime             |              |



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   +----------------------------+----------------------+--------------+
   | date-time-at-processing    | dateTime             |              |
   +----------------------------+----------------------+--------------+
   | date-time-at-completed     | dateTime             |              |
   +----------------------------+----------------------+--------------+
   | number-of-intervening-jobs | integer (0:MAX)      |              |
   +----------------------------+----------------------+--------------+
   | job-message-from-operator  | text (127)           |              |
   +----------------------------+----------------------+--------------+
   | job-k-octets               | integer (0:MAX)      |              |
   +----------------------------+----------------------+--------------+
   | job-impressions            | integer (0:MAX)      |              |
   +----------------------------+----------------------+--------------+
   | job-media-sheets           | integer (0:MAX)      |              |
   +----------------------------+----------------------+--------------+
   | job-k-octets-processed     | integer (0:MAX)      |              |
   +----------------------------+----------------------+--------------+
   | job-impressions-completed  | integer (0:MAX)      |              |
   +----------------------------+----------------------+--------------+
   | job-media-sheets-completed | integer (0:MAX)      |              |
   +----------------------------+----------------------+--------------+
   | attributes-charset         | charset              |  REQUIRED    |
   +----------------------------+----------------------+--------------+
   | attributes-natural-language| naturalLanguage      |  REQUIRED    |
   +----------------------------+----------------------+--------------+

4.3.1 job-uri (uri)

   This REQUIRED attribute contains the URI for the job.  The Printer
   object, on receipt of a new job, generates a URI which identifies the
   new Job.  The Printer object returns the value of the "job-uri"
   attribute as part of the response to a create request.  The precise
   format of a Job URI is implementation dependent.  If the Printer
   object supports more than one URI and there is some relationship
   between the newly formed Job URI and the Printer object's URI, the
   Printer object uses the Printer URI supplied by the client in the
   create request.  For example, if the create request comes in over a
   secure channel, the new Job URI MUST use the same secure channel.
   This can be guaranteed because the Printer object is responsible for
   generating the Job URI and the Printer object is aware of its
   security configuration and policy as well as the Printer URI used in
   the create request.

   For a description of this attribute and its relationship to "job-id"
   and "job-printer-uri" attribute, see the discussion in section 2.4 on
   "Object Identity".





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4.3.2 job-id (integer(1:MAX))

   This REQUIRED attribute contains the ID of the job.  The Printer, on
   receipt of a new job, generates an ID which identifies the new Job on
   that Printer.  The Printer returns the value of the "job-id"
   attribute as part of the response to a create request.  The 0 value
   is not included to allow for compatibility with SNMP index values
   which also cannot be 0.

   For a description of this attribute and its relationship to "job-uri"
   and "job-printer-uri" attribute, see the discussion in section 2.4 on
   "Object Identity".

4.3.3 job-printer-uri (uri)

   This REQUIRED attribute identifies the Printer object that created
   this Job object.  When a Printer object creates a Job object, it
   populates this attribute with the Printer object URI that was used in
   the create request.  This attribute permits a client to identify the
   Printer object that created this Job object when only the Job
   object's URI is available to the client.  The client queries the
   creating Printer object to determine which languages, charsets,
   operations, are supported for this Job.

   For a description of this attribute and its relationship to "job-uri"
   and "job-id" attribute, see the discussion in section 2.4 on "Object
   Identity".

4.3.4 job-more-info (uri)

   Similar to "printer-more-info", this attribute contains the URI
   referencing some resource with more information about this Job
   object, perhaps an HTML page containing information about the Job.

4.3.5 job-name (name(MAX))

   This REQUIRED attribute is the name of the job.  It is a name that is
   more user friendly than the "job-uri" attribute value.  It does not
   need to be unique between Jobs.  The Job's "job-name" attribute is
   set to the value supplied by the client in the "job-name" operation
   attribute in the create request (see Section 3.2.1.1).   If, however,
   the "job-name" operation attribute is not supplied by the client in
   the create request, the Printer object, on creation of the Job, MUST
   generate a name.  The printer SHOULD generate the value of the Job's
   "job-name" attribute from the first of the following sources that
   produces a value: 1) the "document-name" operation attribute of the





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   first (or only) document, 2) the "document-URI" attribute of the
   first (or only) document, or 3) any other piece of Job specific
   and/or Document Content information.

4.3.6 job-originating-user-name (name(MAX))

   This REQUIRED attribute contains the name of the end user that
   submitted the print job.  The Printer object sets this attribute to
   the most authenticated printable name that it can obtain from the
   authentication service over which the IPP operation was received.
   Only if such is not available, does the Printer object use the value
   supplied by the client in the "requesting-user-name" operation
   attribute of the create operation (see Sections 4.4.2, 4.4.3, and 8).

   Note:  The Printer object needs to keep an internal originating user
   id of some form, typically as a credential of a principal, with the
   Job object.  Since such an internal attribute is implementation-
   dependent and not of interest to clients, it is not specified as a
   Job Description attribute.  This originating user id is used for
   authorization checks (if any) on all subsequent operations.

4.3.7 job-state (type1 enum)

   This REQUIRED attribute identifies the current state of the job.
   Even though the IPP protocol defines seven values for job states
   (plus the out-of-band 'unknown' value - see Section 4.1),
   implementations only need to support those states which are
   appropriate for the particular implementation.  In other words, a
   Printer supports only those job states implemented by the output
   device and available to the Printer object implementation.

   Standard enum values are:

   Values Symbolic Name and Description

   '3'  'pending':  The job is a candidate to start processing, but is
           not yet processing.

   '4'  'pending-held':  The job is not a candidate for processing for
           any number of reasons but will return to the 'pending'
           state as soon as the reasons are no longer present.  The
           job's "job-state-reason" attribute MUST indicate why the
           job is no longer a candidate for processing.








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   '5'  'processing':  One or more of:

           1.  the job is using, or is attempting to use, one or
           more purely software processes that are analyzing,
           creating, or interpreting a PDL, etc.,
           2.  the job is using, or is attempting to use, one or
           more hardware devices that are interpreting a PDL, making
           marks on a medium, and/or performing finishing, such as
           stapling, etc.,
           3. the Printer object has made the job ready for
           printing, but the output device is not yet printing it,
           either because the job hasn't reached the output device
           or because the job is queued in the output device or some
           other spooler, awaiting the output device to print it.

           When the job is in the 'processing' state, the entire job
           state includes the detailed status represented in the
           Printer object's "printer-state", "printer-state-
           reasons", and "printer-state-message" attributes.

           Implementations MAY, though they NEED NOT,  include
           additional values in the job's "job-state-reasons"
           attribute to indicate the progress of the job, such as
           adding the 'job-printing' value to indicate when the
           output device is actually making marks on paper and/or
           the 'processing-to-stop-point' value to indicate that the
           IPP object is in the process of canceling or aborting the
           job.  Most implementations won't bother with this nuance.

   '6'  'processing-stopped':  The job has stopped while processing
           for any number of reasons and will return to the
           'processing' state as soon as the reasons are no longer
           present.

           The job's "job-state-reason" attribute MAY indicate why
           the job has stopped processing.  For example, if the
           output device is stopped, the 'printer-stopped' value MAY
           be included in the job's "job-state-reasons" attribute.

           Note:  When an output device is stopped, the device
           usually indicates its condition in human readable form
           locally at the device.  A client can obtain more complete
           device status remotely by querying the Printer object's
           "printer-state", "printer-state-reasons" and "printer-
           state-message" attributes.

   '7'  'canceled':  The job has been canceled by a Cancel-Job
           operation and the Printer object has completed canceling



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           the job and all job status attributes have reached their
           final values for the job.  While the Printer object is
           canceling the job, the job remains in its current state,
           but the job's "job-state-reasons" attribute SHOULD
           contain the 'processing-to-stop-point' value and one of
           the 'canceled-by-user', 'canceled-by-operator', or
           'canceled-at-device' value.  When the job moves to the
           'canceled' state, the  'processing-to-stop-point' value,
           if present, MUST be removed, but the 'canceled-by-xxx',
           if present, MUST remain.

   '8'  'aborted':  The job has been aborted by the system, usually
           while the job was in the 'processing' or 'processing-
           stopped' state and the Printer has completed aborting the
           job and all job status attributes have reached their
           final values for the job.  While the Printer object is
           aborting the job, the job remains in its current state,
           but the job's "job-state-reasons" attribute SHOULD
           contain the 'processing-to-stop-point' and 'aborted-by-
           system' values.  When the job moves to the 'aborted'
           state, the  'processing-to-stop-point' value, if present,
           MUST be removed, but the 'aborted-by-system' value, if
           present, MUST remain.

   '9'  'completed':  The job has completed successfully or with
           warnings or errors after processing and all of the job
           media sheets have been successfully stacked in the
           appropriate output bin(s) and all job status attributes
           have reached their final values for the job.  The job's
           "job-state-reasons" attribute SHOULD contain one of:
           'completed-successfully', 'completed-with-warnings', or
           'completed-with-errors' values.

   The final value for this attribute MUST be one of: 'completed',
   'canceled', or 'aborted' before the Printer removes the job
   altogether.  The length of time that jobs remain in the 'canceled',
   'aborted', and 'completed' states depends on implementation.  See
   section 4.3.7.2.

   The following figure shows the normal job state transitions.

                                                      +----> canceled
                                                     /
       +----> pending --------> processing ---------+------> completed
       |         ^                   ^               \
   --->+         |                   |                +----> aborted
       |         v                   v               /
       +----> pending-held    processing-stopped ---+



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   Normally a job progresses from left to right.  Other state
   transitions are unlikely, but are not forbidden.  Not shown are the
   transitions to the 'canceled' state from the 'pending', 'pending-
   held', and 'processing-stopped' states.

   Jobs reach one of the three terminal states: 'completed', 'canceled',
   or 'aborted', after the jobs have completed all activity, including
   stacking output media, after the jobs have completed all activity,
   and all job status attributes have reached their final values for the
   job.

4.3.7.1 Forwarding Servers

   As with all other IPP attributes, if the implementation cannot
   determine the correct value for this attribute, it SHOULD respond
   with the out-of-band value 'unknown' (see section 4.1) rather than
   try to guess at some possibly incorrect value and give the end user
   the wrong impression about the state of the Job object.  For example,
   if the implementation is just a gateway into some printing system
   from which it can normally get status, but temporarily is unable,
   then the implementation should return the 'unknown' value.  However,
   if the implementation is a gateway to a printing system that never
   provides detailed status about the print job, the implementation MAY
   set the IPP Job object's state  to 'completed', provided that it also
   sets the 'queued-in-device' value in the job's "job-state-reasons"
   attribute (see section 4.3.8).

4.3.7.2 Partitioning of Job States

   This section partitions the 7 job states into phases:  Job Not
   Completed, Job Retention, Job History, and Job Removal.  This section
   also explains the 'job-restartable' value of the "job-state-reasons"
   Job Description attribute for use with the Restart-Job operation.

   Job Not Completed:  When a job is in the 'pending', 'pending-held',
   'processing', or 'processing-stopped' states, the job is not
   completed.

   Job Retention:  When a job enters one of the three terminal job
   states:  'completed', 'canceled', or 'aborted', the IPP Printer
   object MAY "retain" the job in a restartable condition for an
   implementation-defined time period.  This time period MAY be zero
   seconds and MAY depend on the terminal job state.  This phase is
   called Job Retention.  While in the Job Retention phase, the job's
   document data is retained and a client may restart the job using the
   Restart-Job operation.  If the IPP object supports the Restart-Job





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   operation, then it SHOULD indicate that the job is restartable by
   adding the 'job-restartable' value to the job's "job-state-reasons"
   attribute (see Section 4.3.8) during the Job Retention phase.

   Job History:  After the Job Retention phase expires for a job, the
   Printer object deletes the document data for the job and the job
   becomes part of the Job History.  The Printer object MAY also delete
   any number of the job attributes.  Since the job is no longer
   restartable, the Printer object MUST remove the 'job-restartable'
   value from the job's "job-state-reasons" attribute, if present.

   Job Removal:  After the job has remained in the Job History for an
   implementation-defined time, such as when the number of jobs exceeds
   a fixed number or after a fixed time period (which MAY be zero
   seconds), the IPP Printer removes the job from the system.

   Using the Get-Jobs operation and supplying the 'not-completed' value
   for the "which-jobs" operation attribute, a client is requesting jobs
   in the Job Not Completed phase.  Using the Get-Jobs operation and
   supplying the 'completed' value for the "which-jobs" operation
   attribute, a client is requesting jobs in the Job Retention and Job
   History phases.  Using the Get-Job-Attributes operation, a client is
   requesting a job in any phase except Job Removal.  After Job Removal,
   the Get-Job-Attributes and Get-Jobs operations no longer are capable
   of returning any information about a job.

4.3.8 job-state-reasons (1setOf type2 keyword)

   This REQUIRED attribute provides additional information about the
   job's current state, i.e., information that augments the value of the
   job's "job-state" attribute.

   These values MAY be used with any job state or states for which the
   reason makes sense.  Some of these value definitions indicate
   conformance requirements; the rest are OPTIONAL.  Furthermore, when
   implemented, the Printer MUST return these values when the reason
   applies and MUST NOT return them when the reason no longer applies
   whether the value of the Job's "job-state" attribute changed or not.
   When the Job does not have any reasons for being in its current
   state, the value of the Job's "job-state-reasons" attribute MUST be
   'none'.

   Note: While values cannot be added to the 'job-state' attribute
   without impacting deployed clients that take actions upon receiving
   "job-state" values, it is the intent that additional "job-state-
   reasons" values can be defined and registered without impacting such
   deployed clients.  In other words, the "job-state-reasons" attribute
   is intended to be extensible.



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   The following standard keyword values are defined.  For ease of
   understanding, the values are presented in the order in which the
   reasons are likely to occur (if implemented), starting with the
   'job-incoming' value:

      'none':  There are no reasons for the job's current state.  This
         state reason is semantically equivalent to "job-state-reasons"
         without any value and MUST be used when there is no other
         value, since the 1setOf attribute syntax requires at least one
         value.
      'job-incoming':  Either (1) the Printer has accepted the Create-
         Job operation and is expecting additional Send-Document and/or
         Send-URI operations, or (2) the Printer is retrieving/accepting
         document data as a result of a Print-Job, Print-URI, Send-
         Document or Send-URI operation.
      'job-data-insufficient':  The Create-Job operation has been
         accepted by the Printer, but the Printer is expecting
         additional document data before it can move the job into the
         'processing' state.  If a Printer starts processing before it
         has received all data, the Printer removes the 'job-data-
         insufficient' reason, but the 'job-incoming' remains.  If a
         Printer starts processing after it has received all data, the
         Printer removes the 'job-data-insufficient' reason and the
         'job-incoming' at the same time.
      'document-access-error':  After accepting a Print-URI or Send-URI
         request, the Printer could not access one or more documents
         passed by reference.  This reason is intended to cover any file
         access problem, including file does not exist and access denied
         because of an access control problem.  The Printer MAY also
         indicate the document access error using the "job-document-
         access-errors" Job Description attribute (see section 4.3.11).
         Whether the Printer aborts the job and moves the job to the
         'aborted' job state or prints all documents that are accessible
         and moves the job to the 'completed' job state and adds the
         'completed-with-errors' value in the job's "job-state-reasons"
         attribute depends on implementation and/or site policy.  This
         value SHOULD be supported if the Print-URI or Send-URI
         operations are supported.
      'submission-interrupted':  The job was not completely submitted
         for some unforeseen reason, such as: (1) the Printer has
         crashed before the job was closed by the client, (2) the
         Printer or the document transfer method has crashed in some
         non-recoverable way before the document data was entirely
         transferred to the Printer, (3) the client crashed or failed to
         close the job before the time-out period.  See section 4.4.31.
      'job-outgoing':  The Printer is transmitting the job to the output
         device.




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      'job-hold-until-specified':  The value of the job's "job-hold-
         until" attribute was specified with a time period that is still
         in the future.  The job MUST NOT be a candidate for processing
         until this reason is removed and there are no other reasons to
         hold the job.  This value SHOULD be supported if the "job-
         hold-until" Job Template attribute is supported.
      'resources-are-not-ready':  At least one of the resources needed
         by the job, such as media, fonts, resource objects, etc., is
         not ready on any of the physical printer's for which the job is
         a candidate.  This condition MAY be detected when the job is
         accepted, or subsequently while the job is pending or
         processing, depending on implementation.  The job may remain in
         its current state or be moved to the 'pending-held' state,
         depending on implementation and/or job scheduling policy.
      'printer-stopped-partly':  The value of the Printer's "printer-
         state-reasons" attribute contains the value 'stopped-partly'.
      'printer-stopped':  The value of the Printer's "printer-state"
         attribute is 'stopped'.
      'job-interpreting': Job is in the 'processing' state, but more
         specifically, the Printer is interpreting the document data.
      'job-queued': Job is in the 'processing' state, but more
         specifically, the Printer has queued the document data.
      'job-transforming': Job is in the 'processing' state, but more
         specifically, the Printer is interpreting document data and
         producing another electronic representation.
      'job-queued-for-marker': Job is in any of the 'pending-held',
         'pending', or 'processing' states, but more specifically, the
         Printer has completed enough processing of the document to be
         able to start marking and the job is waiting for the marker.
         Systems that require human intervention to release jobs using
         the Release-Job operation, put the job into the 'pending-held'
         job state.  Systems that automatically select a job to use the
         marker put the job into the  'pending' job state or keep the
         job in the 'processing' job state while waiting for the marker,
         depending on implementation.  All implementations put the job
         into (or back into) the 'processing' state when marking does
         begin.
      'job-printing':  The output device is marking media. This value is
         useful for Printers which spend a great deal of time processing
         (1) when no marking is happening and then want to show that
         marking is now happening or (2) when the job is in the process
         of being canceled or aborted while the job remains in the
         'processing' state, but the marking has not yet stopped so that
         impression or sheet counts are still increasing for the job.







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      'job-canceled-by-user':  The job was canceled by the owner of the
         job using the Cancel-Job request, i.e., by a user whose
         authenticated identity is the same as the value of the
         originating user that created the Job object, or by some other
         authorized end-user, such as a member of the job owner's
         security group.  This value SHOULD be supported.
      'job-canceled-by-operator':  The job was canceled by the operator
         using the Cancel-Job request, i.e., by a user who has been
         authenticated as having operator privileges (whether local or
         remote).  If the security policy is to allow anyone to cancel
         anyone's job, then this value may be used when the job is
         canceled by other than the owner of the job.  For such a
         security policy, in effect, everyone is an operator as far as
         canceling jobs with IPP is concerned.  This value SHOULD be
         supported if the implementation permits canceling by other than
         the owner of the job.
      'job-canceled-at-device':  The job was canceled by an unidentified
         local user, i.e., a user at a console at the device.  This
         value SHOULD be supported if the implementation supports
         canceling jobs at the console.
      'aborted-by-system':  The job (1) is in the process of being
         aborted, (2) has been aborted by the system and placed in the
         'aborted' state, or (3) has been aborted by the system and
         placed in the 'pending-held' state, so that a user or operator
         can manually try the job again.  This value SHOULD be
         supported.
      'unsupported-compression': The job was aborted by the system
         because the Printer determined while attempting to decompress
         the document-data's that the compression is actually not among
         those supported by the Printer.  This value MUST be supported,
         since "compressions is a REQUIRED operation attribute.
      'compression-error': The job was aborted by the system because the
         Printer encountered an error in the document-data while
         decompressing it.  If the Printer posts this reason, the
         document-data has already passed any tests that would have led
         to the 'unsupported-compression' job-state-reason.
      'unsupported-document-format': The job was aborted by the system
         because the document-data's document-format is not among those
         supported by the Printer.  If the client specifies the
         document-format as 'application/octet-stream', the printer MAY
         abort the job and post this reason even though the format is a
         member of the "document-format-supported" printer attribute,
         but not among the auto-sensed document-formats.  This value
         MUST be supported, since "document-format" is a REQUIRED
         operation attribute.






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      'document-format-error': The job was aborted by the system because
         the Printer encountered an error in the document-data while
         processing it.  If the Printer posts this reason, the
         document-data has already passed any tests that would have led
         to the 'unsupported-document-format' job-state-reason.
      'processing-to-stop-point':  The requester has issued a Cancel-Job
         operation or the Printer object has aborted the job, but is
         still performing some actions on the job until a specified stop
         point occurs or job termination/cleanup is completed.

         If the implementation requires some measurable time to cancel
         the job in the 'processing' or 'processing-stopped' job states,
         the IPP object MUST use this value to indicate that the Printer
         object is still performing some actions on the job while the
         job remains in the 'processing' or 'processing-stopped' state.
         After all the job's job description attributes have stopped
         incrementing, the Printer object moves the job from the
         'processing' state to the 'canceled' or
         'aborted' job states.

      'service-off-line':  The Printer is off-line and accepting no
         jobs.  All 'pending' jobs are put into the 'pending-held'
         state.  This situation could be true if the service's or
         document transform's input is impaired or broken.
      'job-completed-successfully':  The job completed successfully.
         This value SHOULD be supported.
      'job-completed-with-warnings':  The job completed with warnings.
         This value SHOULD be supported if the implementation detects
         warnings.
      'job-completed-with-errors':  The job completed with errors (and
         possibly warnings too).  This value SHOULD be supported if the
         implementation detects errors.
      'job-restartable' - This job is retained (see section 4.3.7.2) and
         is currently able to be restarted using the Restart-Job
         operation (see section 3.3.7).  If 'job-restartable' is a value
         of the job's 'job-state-reasons' attribute, then the IPP object
         MUST accept a Restart-Job operation for that job.  This value
         SHOULD be supported if the Restart-Job operation is supported.
      'queued-in-device': The job has been forwarded to a device or
         print system that is unable to send back status.  The Printer
         sets the job's "job-state " attribute to 'completed'  and adds
         the 'queued-in-device' value to the job's "job-state-reasons"
         attribute to indicate that the Printer has no additional
         information about the job and never will have any better
         information.  See section 4.3.7.1.






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4.3.9 job-state-message (text(MAX))

   This attribute specifies information about the "job-state" and "job-
   state-reasons" attributes in human readable text.  If the Printer
   object supports this attribute, the Printer object MUST be able to
   generate this message in any of the natural languages identified by
   the Printer's "generated-natural-language-supported" attribute (see
   the "attributes-natural-language" operation attribute specified in
   Section 3.1.4.1).

   The value SHOULD NOT contain additional information not contained in
   the values of the "job-state" and "job-states-reasons" attributes,
   such as interpreter error information.  Otherwise, application
   programs might attempt to parse the (localized text).  For such
   additional information such as interpreter errors for application
   program consumption or specific document access errors, new
   attributes with keyword values, needs to be developed and registered.

4.3.10 job-detailed-status-messages (1setOf text(MAX))

   This attribute specifies additional detailed and technical
   information about the job.  The Printer NEED NOT localize the
   message(s), since they are intended for use by the system
   administrator or other experienced technical persons.  Localization
   might obscure the technical meaning of such messages.  Clients MUST
   NOT attempt to parse the value of this attribute.  See "job-
   document-access-errors" (section 4.3.11) for additional errors that a
   program can process.

4.3.11 job-document-access-errors (1setOf text(MAX))

   This attribute provides additional information about each document
   access error for this job encountered by the Printer after it
   returned a response to the Print-URI or Send-URI operation and
   subsequently attempted to access document(s) supplied in the Print-
   URI or Send-URI operation.  For errors in the protocol that is
   identified by the URI scheme in the "document-uri" operation
   attribute, such as 'http:' or 'ftp:', the error code is returned in
   parentheses, followed by the URI.  For example:

      (404) http://ftp.pwg.org/pub/pwg/ipp/new_MOD/ipp-model-v11.pdf

   Most Internet protocols use decimal error codes (unlike IPP), so the
   ASCII error code representation is in decimal.







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4.3.12 number-of-documents (integer(0:MAX))

   This attribute indicates the number of documents in the job, i.e.,
   the number of Send-Document, Send-URI, Print-Job, or Print-URI
   operations that the Printer has accepted for this job, regardless of
   whether the document data has reached the Printer object or not.

   Implementations supporting the OPTIONAL Create-Job/Send-
   Document/Send-URI operations SHOULD support this attribute so that
   clients can query the number of documents in each job.

4.3.13 output-device-assigned (name(127))

   This attribute identifies the output device to which the Printer
   object has assigned this job.  If an output device implements an
   embedded Printer object, the Printer object NEED NOT set this
   attribute.  If a print server implements a Printer object, the value
   MAY be empty (zero- length string) or not returned until the Printer
   object assigns an output device to the job.  This attribute is
   particularly useful when a single Printer object supports multiple
   devices (so called "fan-out" - see section 2.1).

4.3.14 Event Time Job Description Attributes

   This section defines the Job Description attributes that indicate the
   time at which certain events occur for a job.  If the job event has
   not yet occurred, then the IPP object MUST return the 'no-value'
   out-of-band value (see the beginning of Section 4.1).  The "time-at-
   xxx(integer)" attributes represent time as an 'integer' representing
   the number of seconds since the device was powered up (informally
   called "time ticks").  The "date-time-at-xxx(dateTime)" attributes
   represent time as 'dateTime' representing date and time (including an
   offset from UTC).

   In order to populate these attributes, the Printer object copies the
   value(s) of the following Printer Description attributes at the time
   the event occurs:

      1. the value in the Printer's "printer-up-time" attribute for the
         "time-at-xxx(integer)" attributes

      2. the value in the Printer's "printer-current-time" attribute for
         the "date-time-at-xxx(dateTime)" attributes.

   If the Printer resets its "printer-up-time" attribute to 1 on power-
   up (see section 4.4.29) and has persistent jobs, then it MUST change
   all of jobs' "time-at-xxx(integer)" (time tick) job attributes whose
   events have occurred either to:



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      1. 0 to indicate that the event happened before the most recent
         power up OR

      2. the negative of the number of seconds before the most recent
         power-up that the event took place, though the negative number
         NEED NOT reflect the exact number of seconds.

   If a client queries a "time-at-xxx(integer)" time tick Job attribute
   and finds the value to be 0 or negative, the client MUST assume that
   the event occurred in some life other than the Printer's current
   life.

   Note: A Printer does not change the values of any "date-time-at-
   xxx(dateTime)" job attributes on power-up.

4.3.14.1 time-at-creation (integer(MIN:MAX))

   This REQUIRED attribute indicates the time at which the Job object
   was created.

4.3.14.2 time-at-processing (integer(MIN:MAX))

   This REQUIRED attribute indicates the time at which the Job object
   first began processing after the create operation or the most recent
   Restart-Job operation.  The out-of-band 'no-value' value is returned
   if the job has not yet been in the 'processing' state (see the
   beginning of Section 4.1).

4.3.14.3 time-at-completed (integer(MIN:MAX))

   This REQUIRED attribute indicates the time at which the Job object
   completed (or was canceled or aborted).  The out-of-band 'no-value'
   value is returned if the job has not yet completed, been canceled, or
   aborted (see the beginning of Section 4.1).

4.3.14.4 job-printer-up-time (integer(1:MAX))

   This REQUIRED Job Description attribute indicates the amount of time
   (in seconds) that the Printer implementation has been up and running.
   This attribute is an alias for the "printer-up-time" Printer
   Description attribute (see Section 4.4.29).

   A client MAY request this attribute in a Get-Job-Attributes or Get-
   Jobs request and use the value returned in combination with other
   requested Event Time Job Description Attributes in order to display
   time attributes to a user.  The difference between this attribute and
   the 'integer' value of a "time-at-xxx" attribute is the number of




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   seconds ago that the "time-at-xxx" event occurred.  A client can
   compute the wall-clock time at which the "time-at-xxx" event occurred
   by subtracting this difference from the client's wall-clock time.

4.3.14.5 date-time-at-creation (dateTime)

   This attribute indicates the date and time at which the Job object
   was created.

4.3.14.6 date-time-at-processing (dateTime)

   This attribute indicates the date and time at which the Job object
   first began processing after the create operation or the most recent
   Restart-Job operation.

4.3.14.7 date-time-at-completed (dateTime)

   This attribute indicates the date and time at which the Job object
   completed (or was canceled or aborted).

4.3.15 number-of-intervening-jobs (integer(0:MAX))

   This attribute indicates the number of jobs that are "ahead" of this
   job in the relative chronological order of expected time to complete
   (i.e., the current scheduled order). For efficiency, it is only
   necessary to calculate this value when an operation is performed that
   requests this attribute.

4.3.16 job-message-from-operator (text(127))

   This attribute provides a message from an operator, system
   administrator or "intelligent" process to indicate to the end user
   the reasons for modification or other management action taken on a
   job.

4.3.17 Job Size Attributes

   This sub-section defines job attributes that describe the size of the
   job.  These attributes are not intended to be counters; they are
   intended to be useful routing and scheduling information if known.
   For these attributes, the Printer object may try to compute the value
   if it is not supplied in the create request.  Even if the client does
   supply a value for these three attributes in the create request, the
   Printer object MAY choose to change the value if the Printer object
   is able to compute a value which is more accurate than the client
   supplied value.  The Printer object may be able to determine the
   correct value for these attributes either right at job submission
   time or at any later point in time.



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4.3.17.1 job-k-octets (integer(0:MAX))

   This attribute specifies the total size of the document(s) in K
   octets, i.e., in units of 1024 octets requested to be processed in
   the job.  The value MUST be rounded up, so that a job between 1 and
   1024 octets MUST be indicated as being 1, 1025 to 2048 MUST be 2,
   etc.

   This value MUST NOT include the multiplicative factors contributed by
   the number of copies specified by the "copies" attribute, independent
   of whether the device can process multiple copies without making
   multiple passes over the job or document data and independent of
   whether the output is collated or not.  Thus the value is independent
   of the implementation and indicates the size of the document(s)
   measured in K octets independent of the number of copies.

   This value MUST also not include the multiplicative factor due to a
   copies instruction embedded in the document data.  If the document
   data actually includes replications of the document data, this value
   will include such replication.  In other words, this value is always
   the size of the source document data, rather than a measure of the
   hardcopy output to be produced.

4.3.17.2 job-impressions (integer(0:MAX))

   This attribute specifies the total size in number of impressions of
   the document(s) being submitted (see the definition of impression in
   section 12.2.5).

   As with "job-k-octets", this value MUST NOT include the
   multiplicative factors contributed by the number of copies specified
   by the "copies" attribute, independent of whether the device can
   process multiple copies without making multiple passes over the job
   or document data and independent of whether the output is collated or
   not.  Thus the value is independent of the implementation and
   reflects the size of the document(s) measured in impressions
   independent of the number of copies.

   As with "job-k-octets", this value MUST also not include the
   multiplicative factor due to a copies instruction embedded in the
   document data.  If the document data actually includes replications
   of the document data, this value will include such replication.  In
   other words, this value is always the number of impressions in the
   source document data, rather than a measure of the number of
   impressions to be produced by the job.






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4.3.17.3 job-media-sheets (integer(0:MAX))

   This attribute specifies the total number of media sheets to be
   produced for this job.

   Unlike the "job-k-octets" and the "job-impressions" attributes, this
   value MUST include the multiplicative factors contributed by the
   number of copies specified by the "copies" attribute and a 'number of
   copies' instruction embedded in the document data, if any.  This
   difference allows the system administrator to control the lower and
   upper bounds of both (1) the size of the document(s) with "job-k-
   octets-supported" and "job-impressions-supported" and (2) the size of
   the job with "job-media-sheets-supported".

4.3.18 Job Progress Attributes

   This sub-section defines job attributes that describe the progress of
   the job.  These attributes are intended to be counters.  That is, the
   value for a job that has not started processing MUST be 0.  When the
   job's "job-state" is 'processing' or 'processing-stopped', this value
   is intended to contain the amount of the job that has been processed
   to the time at which the attributes are requested.  When the job
   enters the 'completed', 'canceled', or 'aborted' states, these values
   are the final values for the job.

4.3.18.1 job-k-octets-processed (integer(0:MAX))

   This attribute specifies the total number of octets processed in K
   octets, i.e., in units of 1024 octets so far.  The value MUST be
   rounded up, so that a job between 1 and 1024 octets inclusive MUST be
   indicated as being 1, 1025 to 2048 inclusive MUST be 2, etc.

   For implementations where multiple copies are produced by the
   interpreter with only a single pass over the data, the final value
   MUST be equal to the value of the "job-k-octets" attribute.  For
   implementations where multiple copies are produced by the interpreter
   by processing the data for each copy, the final value MUST be a
   multiple of the value of the "job-k-octets" attribute.

4.3.18.2 job-impressions-completed (integer(0:MAX))

   This job attribute specifies the number of impressions completed for
   the job so far.  For printing devices, the impressions completed
   includes interpreting, marking, and stacking the output.







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4.3.18.3 job-media-sheets-completed (integer(0:MAX))

   This job attribute specifies the media-sheets completed marking and
   stacking for the entire job so far whether those sheets have been
   processed on one side or on both.

4.3.19 attributes-charset (charset)

   This REQUIRED attribute is populated using the value in the client
   supplied "attributes-charset" attribute in the create request.  It
   identifies the charset (coded character set and encoding method) used
   by any Job attributes with attribute syntax 'text' and 'name' that
   were supplied by the client in the create request.  See Section 3.1.4
   for a complete description of the "attributes-charset" operation
   attribute.

   This attribute does not indicate the charset in which the 'text' and
   'name' values are stored internally in the Job object.  The internal
   charset is implementation-defined.  The IPP object MUST convert from
   whatever the internal charset is to that being requested in an
   operation as specified in Section 3.1.4.

4.3.20 attributes-natural-language (naturalLanguage)

   This REQUIRED attribute is populated using the value in the client
   supplied "attributes-natural-language" attribute in the create
   request.  It identifies the natural language used for any Job
   attributes with attribute syntax 'text' and 'name' that were supplied
   by the client in the create request.  See Section 3.1.4 for a
   complete description of the "attributes-natural-language" operation
   attribute.  See Sections 4.1.1.2 and 4.1.2.2 for how a Natural
   Language Override may be supplied explicitly for each 'text' and
   'name' attribute value that differs from the value identified by the
   "attributes-natural-language" attribute.

4.4 Printer Description Attributes

   These attributes form the attribute group called "printer-
   description".  The following table summarizes these attributes, their
   syntax, and whether or not they are REQUIRED for a Printer object to
   support.  If they are not indicated as REQUIRED, they are OPTIONAL.
   The maximum size in octets for 'text' and 'name' attributes is
   indicated in parenthesizes.

   Note: How these attributes are set by an Administrator is outside the
   scope of this IPP/1.1 document.





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  +----------------------------+---------------------------+-----------+
  |      Attribute             |     Syntax                | REQUIRED? |
  +----------------------------+---------------------------+-----------+
  | printer-uri-supported      | 1setOf uri                |  REQUIRED |
  +----------------------------+---------------------------+-----------+
  | uri-security-supported     | 1setOf type2 keyword      |  REQUIRED |
  +----------------------------+---------------------------+-----------+
  | uri-authentication-        | 1setOf type2 keyword      |  REQUIRED |
  |     supported              |                           |           |
  +----------------------------+---------------------------+-----------+
  | printer-name               | name (127)                |  REQUIRED |
  +----------------------------+---------------------------+-----------+
  | printer-location           | text (127)                |           |
  +----------------------------+---------------------------+-----------+
  | printer-info               | text (127)                |           |
  +----------------------------+---------------------------+-----------+
  | printer-more-info          | uri                       |           |
  +----------------------------+---------------------------+-----------+
  | printer-driver-installer   | uri                       |           |
  +----------------------------+---------------------------+-----------+
  | printer-make-and-model     | text (127)                |           |
  +----------------------------+---------------------------+-----------+
  | printer-more-info-         | uri                       |           |
  | manufacturer               |                           |           |
  +----------------------------+---------------------------+-----------+
  | printer-state              | type1 enum                |  REQUIRED |
  +----------------------------+---------------------------+-----------+
  | printer-state-reasons      | 1setOf type2 keyword      |  REQUIRED |
  +----------------------------+---------------------------+-----------+
  | printer-state-message      | text (MAX)                |           |
  +----------------------------+---------------------------+-----------+
  | ipp-versions-supported     | 1setOf type2 keyword      |  REQUIRED |
  +----------------------------+---------------------------+-----------+
  | operations-supported       | 1setOf type2 enum         |  REQUIRED |
  +----------------------------+---------------------------+-----------+
  | multiple-document-jobs-    | boolean                   |           |
  |     supported              |                           |           |
  +----------------------------+---------------------------+-----------+
  | charset-configured         | charset                   |  REQUIRED |
  +----------------------------+---------------------------+-----------+
  | charset-supported          | 1setOf charset            |  REQUIRED |
  +----------------------------+---------------------------+-----------+
  | natural-language-configured| naturalLanguage           |  REQUIRED |
  +----------------------------+---------------------------+-----------+
  | generated-natural-language-| 1setOf naturalLanguage    |  REQUIRED |
  | supported                  |                           |           |
  +----------------------------+---------------------------+-----------+
  | document-format-default    | mimeMediaType             |  REQUIRED |



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  +----------------------------+---------------------------+-----------+
  | document-format-supported  | 1setOf mimeMediaType      |  REQUIRED |
  +----------------------------+---------------------------+-----------+
  | printer-is-accepting-jobs  | boolean                   |  REQUIRED |
  +----------------------------+---------------------------+-----------+
  | queued-job-count           | integer (0:MAX)           |  REQUIRED |
  +----------------------------+---------------------------+-----------+
  | printer-message-from-      | text (127)                |           |
  | operator                   |                           |           |
  +----------------------------+---------------------------+-----------+
  | color-supported            | boolean                   |           |
  +----------------------------+---------------------------+-----------+
  | reference-uri-schemes-     | 1setOf uriScheme          |           |
  |   supported                |                           |           |
  +----------------------------+---------------------------+-----------+
  | pdl-override-supported     | type2 keyword             |  REQUIRED |
  +----------------------------+---------------------------+-----------+
  | printer-up-time            | integer (1:MAX)           |  REQUIRED |
  +----------------------------+---------------------------+-----------+
  | printer-current-time       | dateTime                  |           |
  +----------------------------+---------------------------+-----------+
  | multiple-operation-time-out| integer (1:MAX)           |           |
  +----------------------------+---------------------------+-----------+
  | compression-supported      | 1setOf type3 keyword      |  REQUIRED |
  +----------------------------+---------------------------+-----------+
  | job-k-octets-supported     | rangeOfInteger (0:MAX)    |           |
  +----------------------------+---------------------------+-----------+
  | job-impressions-supported  | rangeOfInteger (0:MAX)    |           |
  +----------------------------+---------------------------+-----------+
  | job-media-sheets-supported | rangeOfInteger (0:MAX)    |           |
  +----------------------------+---------------------------+-----------+
  | pages-per-minute           | integer(0:MAX)            |           |
  +----------------------------+---------------------------+-----------+
  | pages-per-minute-color     | integer(0:MAX)            |           |
  +----------------------------+---------------------------+-----------+

4.4.1 printer-uri-supported (1setOf uri)

   This REQUIRED Printer attribute contains at least one URI for the
   Printer object.  It OPTIONALLY contains more than one URI for the
   Printer object.    An administrator determines a Printer object's
   URI(s) and configures this attribute to contain those URIs by some
   means outside the scope of this IPP/1.1 document.  The precise format
   of this URI is implementation dependent and depends on the protocol.
   See the next two sections for a description of the "uri-security-
   supported" and "uri-authentication-supported" attributes, both of





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   which are the REQUIRED companion attributes to this "printer-uri-
   supported" attribute.  See section 2.4 on Printer object identity and
   section 8.2 on security and URIs for more information.

4.4.2 uri-authentication-supported (1setOf type2 keyword)

   This REQUIRED Printer attribute MUST have the same cardinality
   (contain the same number of values) as the "printer-uri-supported"
   attribute.  This attribute identifies the Client Authentication
   mechanism associated with each URI listed in the "printer-uri-
   supported" attribute. The Printer object uses the specified mechanism
   to identify the authenticated user (see section 8.3).  The "i th"
   value in "uri-authentication-supported" corresponds to the "i th"
   value in "printer-uri-supported" and it describes the authentication
   mechanisms used by the Printer when accessed via that URI.  See
   [RFC2910] for more details on Client Authentication.

   The following standard keyword values are defined:

      'none': There is no authentication mechanism associated with the
         URI.  The Printer object assumes that the authenticated user is
         "anonymous".
      'requesting-user-name': When a client performs an operation whose
         target is the associated URI, the Printer object assumes that
         the authenticated user is specified by the "requesting-user-
         name" Operation attribute (see section 8.3). If the
         "requesting-user-name" attribute is absent in a request, the
         Printer object assumes that the authenticated user is
         "anonymous".
      'basic': When a client performs an operation whose target is the
         associated URI, the Printer object challenges the client with
         HTTP basic authentication [RFC2617]. The Printer object assumes
         that the authenticated user is the name received via the basic
         authentication mechanism.
      'digest': When a client performs an operation whose target is the
         associated URI, the Printer object challenges the client with
         HTTP digest authentication [RFC2617]. The Printer object
         assumes that the authenticated user is the name received via
         the digest authentication mechanism.
      'certificate': When a client performs an operation whose target is
         the associated URI, the Printer object expects the client to
         provide a certificate. The Printer object assumes that the
         authenticated user is the textual name contained within the
         certificate.







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4.4.3 uri-security-supported (1setOf type2 keyword)

   This REQUIRED Printer attribute MUST have the same cardinality
   (contain the same number of values) as the "printer-uri-supported"
   attribute.  This attribute identifies the security mechanisms used
   for each URI listed in the "printer-uri-supported" attribute.  The "i
   th" value in "uri-security-supported" corresponds to the "i th" value
   in "printer-uri-supported" and it describes the security mechanisms
   used for accessing the Printer object via that URI.  See [RFC2910]
   for more details on security mechanisms.

   The following standard keyword values are defined:

      'none': There are no secure communication channel protocols in use
         for the given URI.
      'ssl3': SSL3 [SSL] is the secure communications channel protocol
         in use for the given URI.
      'tls':  TLS [RFC2246] is the secure communications channel
         protocol in use for the given URI.

   This attribute is orthogonal to the definition of a Client
   Authentication mechanism.  Specifically, 'none' does not exclude
   Client Authentication. See section 4.4.2.

   Consider the following example.  For a single Printer object, an
   administrator configures the "printer-uri-supported",  "uri-
   authentication-supported" and "uri-security-supported" attributes as
   follows:

     "printer-uri-supported": 'xxx://acme.com/open-use-printer',
        'xxx://acme.com/restricted-use-printer',
        'xxx://acme.com/private-printer'
     "uri-authentication-supported": 'none', 'digest', 'basic'
     "uri-security-supported": 'none', 'none', 'tls'

   Note:  'xxx'  is not a valid scheme.  See the IPP/1.1 "Transport and
   Encoding" document [RFC2910] for the actual URI schemes to be used in
   object target attributes.

   In this case, one Printer object has three URIs.

      - For the first URI, 'xxx://acme.com/open-use-printer', the value
        'none' in "uri-security-supported" indicates that there is no
        secure channel protocol configured to run under HTTP.  The value
        of 'none' in "uri-authentication-supported" indicates that all
        users are 'anonymous'.  There will be no challenge and the
        Printer will ignore "requesting-user-name".




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      - For the second URI, 'xxx://acme.com/restricted-use-printer', the
        value 'none' in "uri-security-supported" indicates that there is
        no secure channel protocol configured to run under HTTP. The
        value of 'digest' in "uri-authentication-supported" indicates
        that the Printer will issue a challenge and that the Printer
        will use the name supplied by the digest mechanism to determine
        the authenticated user (see section 8.3).
      - For the third URI, 'xxx://acme.com/private-printer', the value
        'tls' in "uri-security-supported" indicates that TLS is being
        used to secure the channel.  The client SHOULD be prepared to
        use TLS framing to negotiate an acceptable ciphersuite to use
        while communicating with the Printer object.  In this case, the
        name implies the use of a secure communications channel, but the
        fact is made explicit by the presence of the 'tls' value in
        "uri-security-supported".  The client does not need to resort to
        understanding which security it must use by following naming
        conventions or by parsing the URI to determine which security
        mechanisms are implied.  The value of 'basic' in "uri-
        authentication-supported" indicates that the Printer will issue
        a challenge and that the Printer will use the name supplied by
        the digest mechanism to determine the authenticated user (see
        section 8.3).  Because this challenge occurs in a tls session,
        the channel is secure.

   It is expected that many IPP Printer objects will be configured to
   support only one channel (either configured to use TLS access or not)
   and only one authentication mechanism. Such Printer objects only have
   one URI listed in the "printer-uri-supported" attribute.  No matter
   the configuration of the Printer object (whether it has only one URI
   or more than one URI), a client MUST supply only one URI in the
   target "printer-uri" operation attribute.

4.4.4 printer-name (name(127))

   This REQUIRED Printer attribute contains the name of the Printer
   object.  It is a name that is more end-user friendly than a URI. An
   administrator determines a printer's name and sets this attribute to
   that name. This name may be the last part of the printer's URI or it
   may be unrelated.  In non-US-English locales, a name may contain
   characters that are not allowed in a URI.

4.4.5 printer-location (text(127))

   This Printer attribute identifies the location of the device. This
   could include things like: "in Room 123A, second floor of building
   XYZ".





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4.4.6 printer-info (text(127))

   This Printer attribute identifies the descriptive information about
   this Printer object.  This could include things like: "This printer
   can be used for printing color transparencies for HR presentations",
   or "Out of courtesy for others, please print only small (1-5 page)
   jobs at this printer", or even "This printer is going away on July 1,
   1997, please find a new printer".

4.4.7 printer-more-info (uri)

   This Printer attribute contains a URI used to obtain more information
   about this specific Printer object.  For example, this could be an
   HTTP type URI referencing an HTML page accessible to a Web Browser.
   The information obtained from this URI is intended for end user
   consumption.  Features outside the scope of IPP can be accessed from
   this URI.  The information is intended to be specific to this printer
   instance and site specific services (e.g. job pricing, services
   offered, end user assistance). The device manufacturer may initially
   populate this attribute.

4.4.8 printer-driver-installer (uri)

   This Printer attribute contains a URI to use to locate the driver
   installer for this Printer object.   This attribute is intended for
   consumption by automata.  The mechanics of print driver installation
   is outside the scope of this IPP/1.1 document.  The device
   manufacturer may initially populate this attribute.

4.4.9 printer-make-and-model (text(127))

   This Printer attribute identifies the make and model of the device.
   The device manufacturer may initially populate this attribute.

4.4.10 printer-more-info-manufacturer (uri)

   This Printer attribute contains a URI used to obtain more information
   about this type of device.  The information obtained from this URI is
   intended for end user consumption.  Features outside the scope of IPP
   can be accessed from this URI (e.g., latest firmware, upgrades, print
   drivers, optional features available, details on color support).  The
   information is intended to be germane to this printer without regard
   to site specific modifications or services. The device manufacturer
   may initially populate this attribute.







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4.4.11 printer-state (type1 enum)

   This REQUIRED Printer attribute identifies the current state of the
   device.  The "printer-state reasons" attribute augments the
   "printer-state" attribute to give more detailed information about the
   Printer in the given printer state.

   A Printer object need only update this attribute before responding to
   an operation which requests the attribute; the Printer object NEED
   NOT update this attribute continually, since asynchronous event
   notification is not part of IPP/1.1.  A Printer NEED NOT implement
   all values if they are not applicable to a given implementation.

   The following standard enum values are defined:

   Value  Symbolic Name and Description

   '3'    'idle':  Indicates that new jobs can start processing without
                waiting.
   '4'    'processing':  Indicates that jobs are processing; new jobs
                will wait before processing.
   '5'    'stopped':  Indicates that no jobs can be processed and
                intervention is required.

   Values of "printer-state-reasons", such as 'spool-area-full' and
   'stopped-partly', MAY be used to provide further information.

4.4.12 printer-state-reasons (1setOf type2 keyword)

   This REQUIRED Printer attribute supplies additional detail about the
   device's state.  Some of the these value definitions indicate
   conformance requirements; the rest are OPTIONAL.

   Each keyword value MAY have a suffix to indicate its level of
   severity.  The three levels are: report (least severe), warning, and
   error (most severe).

      - '-report':  This suffix indicates that the reason is a "report".
        An implementation may choose to omit some or all reports. Some
        reports specify finer granularity about the printer state;
        others serve as a precursor to a warning. A report MUST contain
        nothing that could affect the printed output.
      - '-warning': This suffix indicates that the reason is a
        "warning".  An implementation may choose to omit some or all
        warnings. Warnings serve as a precursor to an error. A warning
        MUST contain nothing that prevents a job from completing, though
        in some cases the output may be of lower quality.




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      - '-error': This suffix indicates that the reason is an "error".
        An implementation MUST include all errors. If this attribute
        contains one or more errors, printer MUST be in the stopped
        state.

   If the implementation does not add any one of the three suffixes, all
   parties MUST assume that the reason is an "error".

   If a Printer object controls more than one output device, each value
   of this attribute MAY apply to one or more of the output devices.  An
   error on one output device that does not stop the Printer object as a
   whole MAY appear as a warning in the Printer's "printer-state-reasons
   attribute".  If the "printer-state" for such a Printer has a value of
   'stopped', then there MUST be an error reason among the values in the
   "printer-state-reasons" attribute.

   The following standard keyword values are defined:

      'other': The device has detected an error other than one listed in
         this document.
      'none': There are not reasons. This state reason is semantically
         equivalent to "printer-state-reasons" without any value and
         MUST be used, since the 1setOf attribute syntax requires at
         least one value.
      'media-needed': A tray has run out of media.
      'media-jam': The device has a media jam.
      'moving-to-paused':  Someone has paused the Printer object using
         the Pause-Printer operation (see section 3.2.7) or other means,
         but the device(s) are taking an appreciable time to stop.
         Later, when all output has stopped, the "printer-state" becomes
         'stopped', and the 'paused' value replaces the 'moving-to-
         paused' value in the "printer-state-reasons" attribute.  This
         value MUST be supported, if the Pause-Printer operation is
         supported and the implementation takes significant time to
         pause a device in certain circumstances.
      'paused': Someone has paused the Printer object using the Pause-
         Printer operation (see section 3.2.7) or other means and the
         Printer object's "printer-state" is 'stopped'.  In this state,
         a Printer MUST NOT produce printed output, but it MUST perform
         other operations requested by a client.  If a Printer had been
         printing a job when the Printer was paused, the Printer MUST
         resume printing that job when the Printer is no longer paused
         and leave no evidence in the printed output of such a pause.
         This value MUST be supported, if the Pause-Printer operation is
         supported.
      'shutdown': Someone has removed a Printer object from service, and
         the device may be powered down or physically removed.  In this
         state, a Printer object MUST NOT produce printed output, and



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         unless the Printer object is realized by a print server that is
         still active, the Printer object MUST perform no other
         operations requested by a client, including returning this
         value. If a Printer object had been printing a job when it was
         shutdown, the Printer NEED NOT resume printing that job when
         the Printer is no longer shutdown. If the Printer resumes
         printing such a job, it may leave evidence in the printed
         output of such a shutdown, e.g. the part printed before the
         shutdown may be printed a second time after the shutdown.
      'connecting-to-device': The Printer object has scheduled a job on
         the output device and is in the process of connecting to a
         shared network output device (and might not be able to actually
         start printing the job for an arbitrarily long time depending
         on the usage of the output device by other servers on the
         network).
      'timed-out': The server was able to connect to the output device
         (or is always connected), but was unable to get a response from
         the output device.
      'stopping': The Printer object is in the process of stopping the
         device and will be stopped in a while. When the device is
         stopped, the Printer object will change the Printer object's
         state to 'stopped'.  The 'stopping-warning' reason is never an
         error, even for a Printer with a single output device.  When an
         output-device ceases accepting jobs, the Printer will have this
         reason while the output device completes printing.
      'stopped-partly': When a Printer object controls more than one
         output device, this reason indicates that one or more output
         devices are stopped.  If the reason is a report, fewer than
         half of the output devices are stopped.  If the reason is a
         warning, fewer than all of the output devices are stopped.
      'toner-low': The device is low on toner.
      'toner-empty':  The device is out of toner.
      'spool-area-full': The limit of persistent storage allocated for
         spooling has been reached.  The Printer is temporarily unable
         to accept more jobs.  The Printer will remove this value when
         it is able to accept more jobs.  This value SHOULD be used by a
         non-spooling Printer that only accepts one or a small number
         jobs at a time or a spooling Printer that has filled the spool
         space.
      'cover-open': One or more covers on the device are open.
      'interlock-open': One or more interlock devices on the printer are
         unlocked.
      'door-open': One or more doors on the device are open.
      'input-tray-missing': One or more input trays are not in the
         device.
      'media-low': At least one input tray is low on media.
      'media-empty': At least one input tray is empty.




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      'output-tray-missing': One or more output trays are not in the
         device
      'output-area-almost-full': One or more output area is almost full
         (e.g. tray, stacker, collator).
      'output-area-full': One or more output area is full. (e.g. tray,
         stacker, collator)
      'marker-supply-low': The device is low on at least one marker
         supply.  (e.g. toner, ink, ribbon)
      'marker-supply-empty: The device is out of at least one marker
         supply. (e.g. toner, ink, ribbon)
      'marker-waste-almost-full': The device marker supply waste
         receptacle is almost full.
      'marker-waste-full': The device marker supply waste receptacle is
         full.
      'fuser-over-temp': The fuser temperature is above normal.
      'fuser-under-temp': The fuser temperature is below normal.
      'opc-near-eol': The optical photo conductor is near end of life.
      'opc-life-over': The optical photo conductor is no longer
         functioning.
      'developer-low': The device is low on developer.
      'developer-empty: The device is out of developer.
      'interpreter-resource-unavailable': An interpreter resource is
         unavailable (i.e. font, form)

4.4.13 printer-state-message (text(MAX))

   This Printer attribute specifies information about the "printer-
   state" and "printer-state-reasons" attributes in human readable text.
   If the Printer object supports this attribute, the Printer object
   MUST be able to generate this message in any of the natural languages
   identified by the Printer's "generated-natural-language-supported"
   attribute (see the "attributes-natural-language" operation attribute
   specified in Section 3.1.4.1).

4.4.14 ipp-versions-supported (1setOf type2 keyword)

   This REQUIRED attribute identifies the IPP protocol version(s) that
   this Printer supports, including major and minor versions, i.e., the
   version numbers for which this Printer implementation meets the
   conformance requirements.  For version number validation, the Printer
   matches the (two-octet binary) "version-number" parameter supplied by
   the client in each request (see sections 3.1.1 and 3.1.8) with the
   (US-ASCII) keyword values of this attribute.








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   The following standard keyword values are defined:

      '1.0': Meets the conformance requirement of IPP version 1.0 as
         specified in RFC 2566 [RFC2566] and RFC 2565 [RFC2565]
         including any extensions registered according to Section 6 and
         any extension defined in this version or any future version of
         the IPP "Model and Semantics" document or the IPP "Encoding and
         Transport" document following the rules, if any, when the
         "version-number" parameter is '1.0'.
      '1.1': Meets the conformance requirement of IPP version 1.1 as
         specified in this document and [RFC2910] including any
         extensions registered according to Section 6 and any extension
         defined in any future versions of the IPP "Model and Semantics"
         document or the IPP Encoding and Transport document following
         the rules, if any, when the "version-number" parameter is
         '1.1'.

4.4.15 operations-supported (1setOf type2 enum)

   This REQUIRED Printer attribute specifies the set of supported
   operations for this Printer object and contained Job objects.

   This attribute is encoded as any other enum attribute syntax
   according to [RFC2910] as 32-bits.  However, all 32-bit enum values
   for this attribute MUST NOT exceed 0x00008FFF, since these same
   values are also passed in two octets in the "operation-id" parameter
   (see section 3.1.1) in each Protocol request with the two high order
   octets omitted in order to indicate the operation being performed
   [RFC2910].

   The following standard enum and "operation-id" (see section 3.1.2)
   values are defined:



















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     Value               Operation Name
     -----------------   -------------------------------------

     0x0000              reserved, not used
     0x0001              reserved, not used
     0x0002              Print-Job
     0x0003              Print-URI
     0x0004              Validate-Job
     0x0005              Create-Job
     0x0006              Send-Document
     0x0007              Send-URI
     0x0008              Cancel-Job
     0x0009              Get-Job-Attributes
     0x000A              Get-Jobs
     0x000B              Get-Printer-Attributes
     0x000C              Hold-Job
     0x000D              Release-Job
     0x000E              Restart-Job
     0x000F              reserved for a future operation
     0x0010              Pause-Printer
     0x0011              Resume-Printer
     0x0012              Purge-Jobs
     0x0013-0x3FFF       reserved for future IETF standards track
                         operations (see section 6.4)
     0x4000-0x8FFF       reserved for vendor extensions (see section 6.4)

4.4.16 multiple-document-jobs-supported (boolean)

   This Printer attribute indicates whether or not the Printer supports
   more than one document per job, i.e., more than one Send-Document or
   Send-Data operation with document data.  If the Printer supports the
   Create-Job and Send-Document operations (see section 3.2.4 and
   3.3.1), it MUST support this attribute.

4.4.17 charset-configured (charset)

   This REQUIRED Printer attribute identifies the charset that the
   Printer object has been configured to represent 'text' and 'name'
   Printer attributes that are set by the operator, system
   administrator, or manufacturer, i.e., for "printer-name" (name),
   "printer-location" (text), "printer-info" (text), and "printer-make-
   and-model" (text).  Therefore, the value of the Printer object's
   "charset-configured" attribute MUST also be among the values of the
   Printer object's "charset-supported" attribute.







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4.4.18 charset-supported (1setOf charset)

   This REQUIRED Printer attribute identifies the set of charsets that
   the Printer and contained Job objects support in attributes with
   attribute syntax 'text' and 'name'. At least the value 'utf-8' MUST
   be present, since IPP objects MUST support the UTF-8 [RFC2279]
   charset.  If a Printer object supports a charset, it means that for
   all attributes of syntax 'text' and 'name' the IPP object MUST (1)
   accept the charset in requests and return the charset in responses as
   needed.

   If more charsets than UTF-8 are supported, the IPP object MUST
   perform charset conversion between the charsets as described in
   Section 3.1.4.2.

4.4.19 natural-language-configured (naturalLanguage)

   This REQUIRED Printer attribute identifies the natural language that
   the Printer object has been configured to represent 'text' and 'name'
   Printer attributes that are set by the operator, system
   administrator, or manufacturer, i.e., for "printer-name" (name),
   "printer-location" (text), "printer-info" (text), and "printer-make-
   and-model" (text).  When returning these Printer attributes, the
   Printer object MAY return them in the configured natural language
   specified by this attribute, instead of the natural language
   requested by the client in the "attributes-natural-language"
   operation attribute.  See Section 3.1.4.1 for the specification of
   the OPTIONAL multiple natural language support.  Therefore, the value
   of the Printer object's "natural-language-configured" attribute MUST
   also be among the values of the Printer object's "generated-natural-
   language-supported" attribute.

4.4.20 generated-natural-language-supported (1setOf naturalLanguage)

   This REQUIRED Printer attribute identifies the natural language(s)
   that the Printer object and contained Job objects support in
   attributes with attribute syntax 'text' and 'name'.  The natural
   language(s) supported depends on implementation and/or configuration.
   Unlike charsets, IPP objects MUST accept requests with any natural
   language or any Natural Language Override whether the natural
   language is supported or not.

   If a Printer object supports a natural language, it means that for
   any of the attributes for which the Printer or Job object generates
   messages, i.e., for the "job-state-message" and "printer-state-
   message" attributes and Operation Messages (see Section 3.1.5) in
   operation responses, the Printer and Job objects MUST be able to




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   generate messages in any of the Printer's supported natural
   languages.  See section 3.1.4 for the definition of 'text' and 'name'
   attributes in operation requests and responses.

   Note: A Printer object that supports multiple natural languages,
   often has separate catalogs of messages, one for each natural
   language supported.

4.4.21 document-format-default (mimeMediaType)

   This REQUIRED Printer attribute identifies the document format that
   the Printer object has been configured to assume if the client does
   not supply a "document-format" operation attribute in any of the
   operation requests that supply document data.  The standard values
   for this attribute are Internet Media types (sometimes called MIME
   types).  For further details see the description of the
   'mimeMediaType' attribute syntax in Section 4.1.9.

4.4.22 document-format-supported (1setOf mimeMediaType)

   This REQUIRED Printer attribute identifies the set of document
   formats that the Printer object and contained Job objects can
   support. For further details see the description of the
   'mimeMediaType' attribute syntax in Section 4.1.9.

4.4.23 printer-is-accepting-jobs (boolean)

   This REQUIRED Printer attribute indicates whether the printer is
   currently able to accept jobs, i.e., is accepting Print-Job, Print-
   URI, and Create-Job requests.  If the value is 'true', the printer is
   accepting jobs.  If the value is 'false', the Printer object is
   currently rejecting any jobs submitted to it.  In this case, the
   Printer object returns the 'server-error-not-accepting-jobs' status
   code.

   This value is independent of the "printer-state" and "printer-state-
   reasons" attributes because its value does not affect the current
   job; rather it affects future jobs.  This attribute, when 'false',
   causes the Printer to reject jobs even when the "printer-state" is
   'idle' or, when 'true', causes the Printer object to accepts jobs
   even when the "printer-state" is 'stopped'.

4.4.24 queued-job-count (integer(0:MAX))

   This REQUIRED Printer attribute contains a count of the number of
   jobs that are either 'pending', 'processing', 'pending-held', or
   'processing-stopped' and is set by the Printer object.




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4.4.25 printer-message-from-operator (text(127))

   This Printer attribute provides a message from an operator, system
   administrator or "intelligent" process to indicate to the end user
   information or status of the printer, such as why it is unavailable
   or when it is expected to be available.

4.4.26 color-supported (boolean)

   This Printer attribute identifies whether the device is capable of
   any type of color printing at all, including highlight color.  All
   document instructions having to do with color are embedded within the
   document PDL (none are external IPP attributes in IPP/1.1).

   Note:  end-users are able to determine the nature and details of the
   color support by querying the "printer-more-info-manufacturer"
   Printer attribute.

4.4.27 reference-uri-schemes-supported (1setOf uriScheme)

   This Printer attribute specifies which URI schemes are supported for
   use in the "document-uri" operation attribute of the Print-URI or
   Send-URI operation.  If a Printer object supports these optional
   operations, it MUST support the "reference-uri-schemes-supported"
   Printer attribute with at least the following schemed URI value:

      'ftp':  The Printer object will use an FTP 'get' operation as
         defined in RFC 2228 [RFC2228] using FTP URLs as defined by
         [RFC2396] and [RFC2316].

   The Printer object MAY OPTIONALLY support other URI schemes (see
   section 4.1.6).

4.4.28 pdl-override-supported (type2 keyword)

   This REQUIRED Printer attribute expresses the ability for a
   particular Printer implementation to either attempt to override
   document data instructions with IPP attributes or not.

   This attribute takes on the following keyword values:

      - 'attempted': This value indicates that the Printer object
         attempts to make the IPP attribute values take precedence over
         embedded instructions in the document data, however there is no
         guarantee.
      - 'not-attempted': This value indicates that the Printer object
         makes no attempt to make the IPP attribute values take
         precedence over embedded instructions in the document data.



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   Section 15 contains a full description of how this attribute
   interacts with and affects other IPP attributes, especially the
   "ipp-attribute-fidelity" attribute.

4.4.29 printer-up-time (integer(1:MAX))

   This REQUIRED Printer attribute indicates the amount of time (in
   seconds) that this Printer instance has been up and running.  The
   value is a monotonically increasing value starting from 1 when the
   Printer object is started-up (initialized, booted, etc.).  This value
   is used to populate the Event Time Job Description Job attributes
   "time-at-creation", "time-at-processing", and "time-at-completed"
   (see section 4.3.14).

   If the Printer object goes down at some value 'n', and comes back up,
   the implementation MAY:

      1. Know how long it has been down, and resume at some value
         greater than 'n', or
      2. Restart from 1.

   In other words, if the device or devices that the Printer object is
   representing are restarted or power cycled, the Printer object MAY
   continue counting this value or MAY reset this value to 1 depending
   on implementation.  However, if the Printer object software ceases
   running, and restarts without knowing the last value for "printer-
   up-time", the implementation MUST reset this value to 1.  If this
   value is reset and the Printer has persistent jobs, the Printer MUST
   reset the "time-at-xxx(integer) Event Time Job Description attributes
   according to Section 4.3.14.  An implementation MAY use both
   implementation alternatives, depending on warm versus cold start,
   respectively.

4.4.30 printer-current-time (dateTime)

   This Printer attribute indicates the current date and time.  This
   value is used to populate the Event Time Job Description attributes:
   "date-time-at-creation", "date-time-at-processing", and "date-time-
   at-completed" (see Section 4.3.14).

   The date and time is obtained on a "best efforts basis" and does not
   have to be that precise in order to work in practice.  A Printer
   implementation sets the value of this attribute by obtaining the date
   and time via some implementation-dependent means, such as getting the
   value from a network time server, initialization at time of
   manufacture, or setting by an administrator.  See [IPP-IIG] for
   examples.  If an implementation supports this attribute and the
   implementation knows that it has not yet been set, then the



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   implementation MUST return the value of this attribute using the
   out-of-band 'no-value' meaning not configured.  See the beginning of
   section 4.1.

   The time zone of this attribute NEED NOT be the time zone used by
   people located near the Printer object or device.  The client MUST
   NOT expect that the time zone of any received 'dateTime' value to be
   in the time zone of the client or in the time zone of the people
   located near the printer.

   The client SHOULD display any dateTime attributes to the user in
   client local time by converting the 'dateTime' value returned by the
   server to the time zone of the client, rather than using the time
   zone returned by the Printer in attributes that use the 'dateTime'
   attribute syntax.

4.4.31 multiple-operation-time-out (integer(1:MAX))

   This Printer attributes identifies the minimum time (in seconds) that
   the Printer object waits for additional Send-Document or Send-URI
   operations to follow a still-open Job object before taking  any
   recovery actions, such as the ones indicated in section 3.3.1.  If
   the Printer object supports the Create-Job and Send-Document
   operations (see section 3.2.4 and 3.3.1), it MUST support this
   attribute.

   It is RECOMMENDED that vendors supply a value for this attribute that
   is between 60 and 240 seconds.  An implementation MAY allow a system
   administrator to set this attribute (by means outside this IPP/1.1
   document).  If so, the system administrator MAY be able to set values
   outside this range.

4.4.32 compression-supported (1setOf type3 keyword)

   This REQUIRED Printer attribute identifies the set of supported
   compression algorithms for document data.  Compression only applies
   to the document data; compression does not apply to the encoding of
   the IPP operation itself.  The supported values are used to validate
   the client supplied "compression" operation attributes in Print-Job,
   Send-Document, and Send-URI requests.

   Standard keyword values are :

   'none': no compression is used.
   'deflate':  ZIP public domain inflate/deflate) compression technology
      in RFC 1951 [RFC1951]
   'gzip' GNU zip compression technology described in RFC 1952
      [RFC1952].



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   'compress': UNIX compression technology in RFC 1977 [RFC1977]

4.4.33 job-k-octets-supported (rangeOfInteger(0:MAX))

   This Printer attribute specifies the upper and lower bounds of total
   sizes of jobs in K octets, i.e., in units of 1024 octets. The
   supported values are used to validate the client supplied "job-k-
   octets" operation attributes in create requests.  The corresponding
   job description attribute "job-k-octets" is defined in section
   4.3.17.1.

4.4.34 job-impressions-supported (rangeOfInteger(0:MAX))

   This Printer attribute specifies the upper and lower bounds for the
   number of impressions per job. The supported values are used to
   validate the client supplied "job-impressions" operation attributes
   in create requests.  The corresponding job description attribute
   "job-impressions" is defined in section 4.3.17.2.

4.4.35 job-media-sheets-supported (rangeOfInteger(0:MAX))

   This Printer attribute specifies the upper and lower bounds for the
   number of media sheets per job. The supported values are used to
   validate the client supplied "job-media-sheets" operation attributes
   in create requests.  The corresponding Job attribute "job-media-
   sheets" is defined in section 4.3.17.3.

4.4.36 pages-per-minute (integer(0:MAX))

   This Printer attributes specifies the nominal number of pages per
   minute to the nearest whole number which may be generated by this
   printer (e.g., simplex, black-and-white).  This attribute is
   informative, not a service guarantee.  Generally, it is the value
   used in the marketing literature to describe the device.

   A value of 0 indicates a device that takes more than two minutes to
   process a page.

4.4.37 pages-per-minute-color (integer(0:MAX))

   This Printer attributes specifies the nominal number of pages per
   minute to the nearest whole number which may be generated by this
   printer when printing color (e.g., simplex, color).  For purposes of
   this attribute, "color" means the same as for the "color-supported"
   attribute, namely, the device is capable of any type of color
   printing at all, including highlight color.  This attribute is





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   informative, not a service guarantee.  Generally, it is the value
   used in the marketing literature to describe the color capabilities
   of this device.

   A value of 0 indicates a device that takes more than two minutes to
   process a page.

   If a color device has several color modes, it MAY use the pages-per-
   minute value for this attribute that corresponds to the mode that
   produces the highest number.

   Black and white only printers MUST NOT support this attribute.  If
   this attribute is present, then the "color-supported" Printer
   description attribute MUST be present and have a 'true' value.

   The values of these two attributes returned by the Get-Printer-
   Attributes operation MAY be affected by the "document-format"
   attribute supplied by the client in the Get-Printer-Attributes
   request.  In other words, the implementation MAY have different
   speeds depending on the document format being processed.  See section
   3.2.5.1 Get-Printer-Attributes.

5. Conformance

   This section describes conformance issues and requirements. This
   document introduces model entities such as objects, operations,
   attributes, attribute syntaxes, and attribute values.  These
   conformance sections describe the conformance requirements which
   apply to these model entities.

5.1 Client Conformance Requirements

   This section describes the conformance requirements for a client (see
   section 2.1), whether it be:

      1. contained within software controlled by an end user, e.g.
         activated by the "Print" menu item in an application that sends
         IPP requests or

      2. the print server component that sends IPP requests to either an
         output device or another "downstream" print server.

   A conforming client MUST support all REQUIRED operations as defined
   in this document.  For each attribute included in an operation
   request, a conforming client MUST supply a value whose type and value
   syntax conforms to the requirements of the Model document as
   specified in Sections 3 and 4.  A conforming client MAY supply any




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   IETF standards track extensions and/or vendor extensions in an
   operation request, as long as the extensions meet the requirements in
   Section 6.

   Otherwise, there are no conformance requirements placed on the user
   interfaces provided by IPP clients or their applications.  For
   example, one application might not allow an end user to submit
   multiple documents per job, while another does.  One application
   might first query a Printer object in order to supply a graphical
   user interface (GUI) dialogue box with supported and default values
   whereas a different implementation might not.

   When sending a request, an IPP client NEED NOT supply any attributes
   that are indicated as OPTIONALLY supplied by the client.

   A client MUST be able to accept any of the attribute syntaxes defined
   in Section 4.1, including their full range, that may be returned to
   it in a response from a Printer object.  In particular for each
   attribute that the client supports whose attribute syntax is 'text',
   the client MUST accept and process both the 'textWithoutLanguage' and
   'textWithLanguage' forms.  Similarly, for each attribute that the
   client supports whose attribute syntax is 'name', the client MUST
   accept and process both the 'nameWithoutLanguage' and
   'nameWithLanguage' forms.  For presentation purposes, truncation of
   long attribute values is not recommended.  A recommended approach
   would be for the client implementation to allow the user to scroll
   through long attribute values.

   A response MAY contain attribute groups, attributes, attribute
   syntaxes, values, and status codes that the client does not expect.
   Therefore, a client implementation MUST gracefully handle such
   responses and not refuse to inter-operate with a conforming Printer
   that is returning IETF standards track extension or vendor
   extensions, including attribute groups, attributes, attribute
   syntaxes, attribute values, status codes, and out-of-band attribute
   values that conform to Section 6.  Clients may choose to ignore any
   parameters, attribute groups, attributes, attribute syntaxes, or
   values that they do not understand.

   While a client is sending data to a printer, it SHOULD do its best to
   prevent a channel from being closed by a lower layer when the channel
   is blocked (i.e. flow-controlled off) for whatever reason, e.g. 'out
   of paper' or 'job ahead hasn't freed up enough memory'.  However, the
   layer that launched the print submission (e.g. an end user) MAY close
   the channel in order to cancel the job.  When a client closes a
   channel, a Printer MAY print all or part of the received portion of
   the document.  See the "Encoding and Transport" document [RFC2910]
   for more details.



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   A client MUST support Client Authentication as defined in the IPP/1.1
   Encoding and Transport document [RFC2910].  A client SHOULD support
   Operation Privacy and Server Authentication as defined in the IPP/1.1
   Encoding and Transport document [RFC2910].  See also section 8 of
   this document.

5.2 IPP Object Conformance Requirements

   This section specifies the conformance requirements for conforming
   implementations of IPP objects (see section 2).  These requirements
   apply to an IPP object whether it is:

      (1) an (embedded) device component that accepts IPP requests and
      controls the device or

      (2) a component of a print server that accepts IPP requests (where
      the print server control one or more networked devices using IPP or
      other protocols).

5.2.1 Objects

   Conforming implementations MUST implement all of the model objects as
   defined in this document in the indicated sections:

      Section 2.1 - Printer Object
      Section 2.2 - Job Object

5.2.2 Operations

   Conforming IPP object implementations MUST implement all of the
   REQUIRED model operations, including REQUIRED responses, as defined
   in this document in the indicated sections:

      For a Printer object:
         Print-Job (section 3.2.1)               REQUIRED
         Print-URI (section 3.2.2)               OPTIONAL
         Validate-Job (section 3.2.3)            REQUIRED
         Create-Job (section 3.2.4)              OPTIONAL
         Get-Printer-Attributes (section 3.2.5)  REQUIRED
         Get-Jobs (section 3.2.6)                REQUIRED
         Pause-Printer (section 3.2.7)           OPTIONAL
         Resume-Printer (section 3.2.8)          OPTIONAL
         Purge-Jobs (section 3.2.9)              OPTIONAL








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      For a Job object:
         Send-Document (section 3.3.1)           OPTIONAL
         Send-URI (section 3.3.2)                OPTIONAL
         Cancel-Job (section 3.3.3)              REQUIRED
         Get-Job-Attributes (section 3.3.4)      REQUIRED
         Hold-Job (section 3.3.5)                OPTIONAL
         Release-Job (section 3.3.6)             OPTIONAL
         Restart-Job (section 3.3.7)             OPTIONAL

   Conforming IPP objects MUST support all REQUIRED operation attributes
   and all values of such attributes if so indicated in the description.
   Conforming IPP objects MUST ignore all unsupported or unknown
   operation attributes or operation attribute groups received in a
   request, but MUST reject a request that contains a supported
   operation attribute that contains an unsupported value.

   Conforming IPP objects MAY return operation responses that contain
   attributes groups, attributes names,  attribute syntaxes, attribute
   values, and status codes that are extensions to this standard.  The
   additional attribute groups MAY occur in any order.

   The following section on object attributes specifies the support
   required for object attributes.

5.2.3 IPP Object Attributes

   Conforming IPP objects MUST support all of the REQUIRED object
   attributes, as defined in this document in the indicated sections.

   If an object supports an attribute, it MUST support only those values
   specified in this document or through the extension mechanism
   described in section 5.2.4. It MAY support any non-empty subset of
   these values.  That is, it MUST support at least one of the specified
   values and at most all of them.

5.2.4 Versions

   IPP/1.1 clients MUST meet the conformance requirements for clients
   specified in this document and [RFC2910].  IPP/1.1 clients MUST send
   requests containing a "version-number" parameter with a '1.1' value.

   IPP/1.1 Printer and Job objects MUST meet the conformance
   requirements for IPP objects specified in this document and
   [RFC2910].   IPP/1.1 objects MUST accept requests containing a
   "version-number" parameter with a '1.1' value (or reject the request
   if the operation is not supported).





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   It is beyond the scope of this specification to mandate conformance
   with previous versions.  IPP/1.1 was deliberately designed, however,
   to make supporting previous versions easy.  It is worth noting that,
   at the time of composing this specification (1999), we would expect
   IPP/1.1 Printer implementations to:

     understand any valid request in the format of IPP/1.0, or 1.1;

     respond appropriately with a response containing the same
     "version-number" parameter value used by the client in the request.

   And we would expect IPP/1.1 clients to:

     understand any valid response in the format of IPP/1.0, or 1.1.

   It is recommended that IPP/1.1 clients try supplying alternate
   version numbers if they receive a 'server-error-version-not-
   supported' error return in a response.

5.2.5 Extensions

   A conforming IPP object MAY support IETF standards track extensions
   and vendor extensions, as long as the extensions meet the
   requirements specified in Section 6.

   For each attribute included in an operation response, a conforming
   IPP object MUST return a value whose type and value syntax conforms
   to the requirement of the Model document as specified in Sections 3
   and 4.

5.2.6 Attribute Syntaxes

   An IPP object MUST be able to accept any of the attribute syntaxes
   defined in Section 4.1, including their full range, in any operation
   in which a client may supply attributes or the system administrator
   may configure attributes (by means outside the scope of this IPP/1.1
   document).  In particular for each attribute that the IPP object
   supports whose attribute syntax is 'text', the IPP object MUST accept
   and process both the 'textWithoutLanguage' and 'textWithLanguage'
   forms.  Similarly, for each attribute that the IPP object supports
   whose attribute syntax is 'name', the IPP object MUST accept and
   process both the 'nameWithoutLanguage' and 'nameWithLanguage' forms.
   Furthermore, an IPP object MUST return attributes to the client in
   operation responses that conform to the syntax specified in Section
   4.1, including their full range if supplied previously by a client.






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5.2.7 Security

   An IPP Printer implementation SHOULD contain support for Client
   Authentication as defined in the IPP/1.1 Encoding and Transport
   document [RFC2910].  A Printer implementation MAY allow an
   administrator to configure the Printer so that all, some, or none of
   the users are authenticated.  See also section 8 of this document.

   An IPP Printer implementation SHOULD contain support for Operation
   Privacy and Server Authentication as defined in the IPP/1.1 Encoding
   and Transport document [RFC2910].  A Printer implementation MAY allow
   an administrator to configure the degree of support for Operation
   Privacy and Server Authentication.  See also section 8 of this
   document.

   Security MUST NOT be compromised when a client supplies a lower
   "version-number" parameter in a request.  For example, if an IPP/1.1
   conforming Printer object accepts version '1.0' requests and is
   configured to enforce Digest Authentication, it MUST do the same for
   a version '1.0' request.

5.3 Charset and Natural Language Requirements

   All clients and IPP objects MUST support the 'utf-8' charset as
   defined in section 4.1.7.

   IPP objects MUST be able to accept any client request which correctly
   uses the "attributes-natural-language" operation attribute or the
   Natural Language Override mechanism on any individual attribute
   whether or not the natural language is supported by the IPP object.
   If an IPP object supports a natural language, then it MUST be able to
   translate (perhaps by table lookup) all generated 'text' or 'name'
   attribute values into one of the supported languages (see section
   3.1.4).  That is, the IPP object that supports a natural language
   NEED NOT be a general purpose translator of any arbitrary 'text' or
   'name' value supplied by the client into that natural language.
   However, the object MUST be able to translate (automatically
   generate) any of its own attribute values and messages into that
   natural language.

6. IANA Considerations

   This section describes the procedures for defining semantics for the
   following IETF standards track extensions and vendor extensions to
   the IPP/1.1 Model and Semantics document:

      1. keyword attribute values
      2. enum attribute values



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      3. attributes
      4. attribute syntaxes
      5. operations
      6. attribute groups
      7. status codes
      8. out-of-band attribute values

   Extensions registered for use with IPP/1.1 are OPTIONAL for client
   and IPP object conformance to the IPP/1.1 "Model and Semantics"
   document (this document).

   These extension procedures are aligned with the guidelines as set
   forth by the IESG [IANA-CON].  Section 11 describes how to propose
   new registrations for consideration.  IANA will reject registration
   proposals that leave out required information or do not follow the
   appropriate format described in Section 11.  The IPP/1.1 Model and
   Semantics document may also be extended by an appropriate RFC that
   specifies any of the above extensions.

6.1 Typed 'keyword' and 'enum' Extensions

   IPP allows for 'keyword' and 'enum' extensions (see sections 4.1.2.3
   and 4.1.4).  This document uses prefixes to the 'keyword' and 'enum'
   basic attribute syntax type in order to communicate extra information
   to the reader through its name. This extra information is not
   represented in the protocol because it is unimportant to a client or
   Printer object.  The list below describes the prefixes and their
   meaning.

      "type1":  This IPP specification document must be revised (or
         another IETF standards track document which augments this
         document) to add a new keyword or a new enum.  No vendor
         defined keywords or enums are allowed.

      "type2":  Implementers can, at any time, add new keyword or enum
         values by proposing the complete specification to IANA:

         iana@iana.org

         IANA will forward the registration proposal to the IPP
         Designated Expert who will review the proposal with a mailing
         list that the Designated Expert keeps for this purpose.
         Initially, that list will be the mailing list used by the IPP
         WG:

            ipp@pwg.org

         even after the IPP WG is disbanded as permitted by [IANA-CON].



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         The IPP Designated Expert is appointed by the IESG Area
         Director responsible for IPP, according to [IANA-CON].

         When a type2 keyword or enum is approved, the IPP Designated
         Expert becomes the point of contact for any future maintenance
         that might be required for that registration.

      "type3":  Implementers can, at any time, add new keyword and enum
         values by submitting the complete specification to IANA as for
         type2 who will forward the proposal to the IPP Designated
         Expert.  While no additional technical review is required, the
         IPP Designated Expert may, at his/her discretion, forward the
         proposal to the same mailing list as for type2 registrations
         for advice and comment.

         When a type3 keyword or enum is approved by the IPP Designated
         Expert, the original proposer becomes the point of contact for
         any future maintenance that might be required for that
         registration.

   For type2 and type3 keywords, the proposer includes the name of the
   keyword in the registration proposal and the name is part of the
   technical review.

   After type2 and type3 enums specifications are approved, the IPP
   Designated Expert in consultation with IANA assigns the next
   available enum number for each enum value.

   IANA will publish approved type2 and type3 keyword and enum
   attributes value registration specifications in:

      ftp.isi.edu/iana/assignments/ipp/attribute-values/xxx/yyy.txt

   where xxx is the attribute name that specifies the initial values and
   yyy.txt is a descriptive file name that contains one or more enums or
   keywords approved at the same time.  For example, if several
   additional enums for stapling are approved for use with the
   "finishings" attribute (and "finishings-default" and "finishings-
   supported" attributes), IANA will publish the additional values in
   the file:

      ftp.isi.edu/iana/assignments/ipp/attribute-
      values/finishings/stapling.txt

   Note: Some attributes are defined to be: 'type3 keywords' | 'name'
   which allows for attribute values to be extended by a site
   administrator with administrator defined names.  Such names are not
   registered with IANA.



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   By definition, each of the three types above assert some sort of
   registry or review process in order for extensions to be considered
   valid.  Each higher numbered level (1, 2, 3) tends to be decreasingly
   less stringent than the previous level.   Therefore, any typeN value
   MAY be registered using a process for some typeM where M is less than
   N, however such registration is NOT REQUIRED.  For example, a type3
   value MAY be registered in a type 1 manner (by being included in a
   future version of an IPP specification), however, it is NOT REQUIRED.

   This document defines keyword and enum values for all of the above
   types, including type3 keywords.

   For vendor keyword extensions, implementers SHOULD use keywords with
   a suitable distinguishing prefix, such as "xxx-" where xxx follows
   the syntax rules for keywords (see section 4.1.3) and is the
   (lowercase) fully qualified company name registered with IANA for use
   in domain names [RFC1035].  For example, if the company XYZ Corp. had
   obtained the domain name "XYZ.com", then a vendor keyword 'abc' would
   be: 'xyz.com-abc'.

   Note: RFC 1035 [RFC1035] indicates that while upper and lower case
   letters are allowed in domain names, no significance is attached to
   the case.  That is, two names with the same spelling but different
   case are to be treated as if identical.  Also, the labels in a domain
   name must follow the rules for ARPANET host names:  They must start
   with a letter, end with a letter or digit, and have as interior
   characters only letters, digits, and hyphen.  Labels must be 63
   characters or less.  Labels are separated by the "." character.

   For vendor enum extensions, implementers MUST use values in the
   reserved integer range which is 2**30 to 2**31-1.

6.2 Attribute Extensibility

   Attribute names (see section 4.1.3) are type2 keywords.  Therefore,
   new attributes may be registered and have the same status as
   attributes in this document by following the type2 extension rules.
   For vendor attribute extensions, implementers SHOULD use keywords
   with a suitable distinguishing prefix as described in Section 6.1.

   IANA will publish approved attribute registration specifications as
   separate files:

      ftp.isi.edu/iana/assignments/ipp/attributes/xxx-yyy.txt

   where "xxx-yyy" is the new attribute name.





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   If a new Printer object attribute is defined and its values can be
   affected by a specific document format, its specification needs to
   contain the following sentence:

         "The value of this attribute returned in a Get-Printer-
         Attributes response MAY depend on the "document-format"
         attribute supplied (see Section 3.2.5.1)."

   If the specification does not, then its value in the Get-Printer-
   Attributes response MUST NOT depend on the "document-format" supplied
   in the request.  When a new Job Template attribute is registered, the
   value of the Printer attributes MAY vary with "document-format"
   supplied in the request without the specification having to indicate
   so.

6.3 Attribute Syntax Extensibility

   Attribute syntaxes (see section 4.1) are like type2 enums.
   Therefore, new attribute syntaxes may be registered and have the same
   status as attribute syntaxes in this document by following the type2
   extension rules described in Section 6.1.  The initial set of value
   codes that identify each of the attribute syntaxes have been assigned
   in the "Encoding and Transport" document [RFC2910], including a
   designated range for vendor extension.

   For attribute syntaxes, the IPP Designated Expert in consultation
   with IANA assigns the next attribute syntax code in the appropriate
   range as specified in [RFC2910].  IANA will publish approved
   attribute syntax registration specifications as separate files:

      ftp.isi.edu/iana/assignments/ipp/attribute-syntaxes/xxx-yyy.txt

   where 'xxx-yyy' is the new attribute syntax name.

6.4 Operation Extensibility

   Operations (see section 3) may also be registered following the type2
   procedures described in Section 6.1, though major new operations will
   usually be done by a new standards track RFC that augments this
   document.  For vendor operation extensions, implementers MUST use the
   range for the "operation-id" in requests specified in Section 4.4.15
   "operations-supported" Printer attribute.

   For operations, the IPP Designated Expert in consultation with IANA
   assigns the next operation-id code as specified in Section 4.4.15.
   IANA will publish approved operation registration specifications as
   separate files:




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      ftp.isi.edu/iana/assignments/ipp/operations/Xxx-Yyy.txt

   where "Xxx-Yyy" is the new operation name.

6.5 Attribute Group Extensibility

   Attribute groups (see section 3.1.3) passed in requests and responses
   may be registered following the type2 procedures described in Section
   6.1.  The initial set of attribute group tags have been assigned in
   the "Encoding and Transport" document [RFC2910], including a
   designated range for vendor extension.

   For attribute groups, the IPP Designated Expert in consultation with
   IANA assigns the next attribute group tag code in the appropriate
   range as specified in [RFC2910].  IANA will publish approved
   attribute group registration specifications as separate files:

      ftp.isi.edu/iana/assignments/ipp/attribute-group-tags/xxx-yyy-
      tag.txt

   where 'xxx-yyy-tag' is the new attribute group tag name.

6.6 Status Code Extensibility

   Operation status codes (see section 3.1.6.1) may also be registered
   following the type2 procedures described in Section 6.1.  The values
   for status codes are allocated in ranges as specified in Section 14
   for each status code class:

      "informational" - Request received, continuing process
      "successful" - The action was successfully received, understood, and
         accepted
      "redirection" - Further action must be taken in order to complete the
         request
      "client-error" - The request contains bad syntax or cannot be
         fulfilled
      "server-error" - The IPP object  failed to fulfill an apparently
         valid request

   For vendor operation status code extensions, implementers MUST use
   the top of each range as specified in Section 13.

   For operation status codes, the IPP Designated Expert in consultation
   with IANA assigns the next status code in the appropriate class range
   as specified in Section 13.  IANA will publish approved status code
   registration specifications as separate files:

      ftp.isi.edu/iana/assignments/ipp/status-codes/xxx-yyy.txt



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   where "xxx-yyy" is the new operation status code keyword.

6.7 Out-of-band Attribute Value Extensibility

   Out-of-band attribute values (see the beginning of section 4.1)
   passed in requests and responses may be registered following the
   type2 procedures described in Section 6.1.  The initial set of out-
   of-band attribute value tags have been assigned in the "Encoding and
   Transport" document [RFC2910].

   For out-of-band attribute value tags, the IPP Designated Expert in
   consultation with IANA assigns the next out-of-band attribute value
   tag code in the appropriate range as specified in [RFC2910].  IANA
   will publish approved out-of-band attribute value tags registration
   specifications as separate files:

      ftp.isi.edu/iana/assignments/ipp/out-of-band-attribute-value-
      tags/xxx-yyy-tag.txt

   where 'xxx-yyy-tag' is the new out-of-band attribute value tag name.

6.8 Registration of MIME types/sub-types for document-formats

   The "document-format" attribute's syntax is 'mimeMediaType'.  This
   means that valid values are Internet Media Types (see Section 4.1.9).
   RFC 2045 [RFC2045] defines the syntax for valid Internet media types.
   IANA is the registry for all Internet media types.

6.9 Registration of charsets for use in 'charset' attribute values

   The "attributes-charset" attribute's syntax is 'charset'.  This means
   that valid values are charsets names.  When a charset in the IANA
   registry has more than one name (alias), the name labeled as
   "(preferred MIME name)", if present, MUST be used (see Section
   4.1.7).  IANA is the registry for charsets following the procedures
   of [RFC2278].

7. Internationalization Considerations

   Some of the attributes have values that are text strings and names
   which are intended for human understanding rather than machine
   understanding (see the 'text' and 'name' attribute syntaxes in
   Sections 4.1.1 and 4.1.2).

   In each operation request, the client

      - identifies the charset and natural language of the request which
        affects each supplied 'text' and 'name' attribute value, and



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      - requests the charset and natural language for attributes
        returned by the IPP object in operation responses (as described
        in Section 3.1.4.1).

   In addition, the client MAY separately and individually identify the
   Natural Language Override of a supplied 'text' or 'name' attribute
   using the 'textWithLanguage' and 'nameWithLanguage' technique
   described section 4.1.1.2 and 4.1.2.2 respectively.

   All IPP objects MUST support the UTF-8 [RFC2279] charset in all
   'text' and 'name' attributes supported.  If an IPP object supports
   more than the UTF-8 charset, the object MUST convert between them in
   order to return the requested charset to the client according to
   Section 3.1.4.2.  If an IPP object supports more than one natural
   language, the object SHOULD return 'text' and 'name' values in the
   natural language requested where those values are generated by the
   Printer (see Section 3.1.4.1).

   For Printers that support multiple charsets and/or multiple natural
   languages in 'text' and 'name' attributes, different jobs may have
   been submitted in differing charsets and/or natural languages.  All
   responses MUST be returned in the charset requested by the client.
   However, the Get-Jobs operation uses the 'textWithLanguage' and
   'nameWithLanguage' mechanism to identify the differing natural
   languages with each job attribute returned.

   The Printer object also has configured charset and natural language
   attributes.   The client can query the Printer object to determine
   the list of charsets and natural languages supported by the Printer
   object and what the Printer object's configured values are.  See the
   "charset-configured", "charset-supported", "natural-language-
   configured", and "generated-natural-language-supported" Printer
   description attributes for more details.

   The "charset-supported" attributed identifies the supported charsets.
   If a charset is supported, the IPP object MUST be capable of
   converting to and from that charset into any other supported charset.
   In many cases, an IPP object will support only one charset and it
   MUST be the UTF-8 charset.

   The "charset-configured" attribute identifies the one supported
   charset which is the native charset given the current configuration
   of the IPP object (administrator defined).

   The "generated-natural-language-supported" attribute identifies the
   set of supported natural languages for generated messages; it is not
   related to the set of natural languages that must be accepted for
   client supplied 'text' and 'name' attributes.  For client supplied



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   'text' and 'name' attributes, an IPP object MUST accept ALL supplied
   natural languages.  Just because a Printer object is currently
   configured to support 'en-us' natural language does not mean that the
   Printer object should reject a job if the client supplies a job name
   that is in 'fr-ca'.

   The "natural-language-configured" attribute identifies the one
   supported natural language for generated messages which is the native
   natural language given the current configuration of the IPP object
   (administrator defined).

   Attributes of type 'text' and 'name' are populated from different
   sources.  These attributes can be categorized into following groups
   (depending on the source of the attribute):

      1. Some attributes are supplied by the client (e.g., the client
         supplied "job-name", "document-name", and "requesting-user-
         name" operation attributes along with the corresponding Job
         object's "job-name" and "job-originating-user-name"
         attributes).  The IPP object MUST accept these attributes in
         any natural language no matter what the set of supported
         languages for generated messages
      2. Some attributes are supplied by the system administrator (e.g.,
         the Printer object's "printer-name" and "printer-location"
         attributes).  These too can be in any natural language.  If the
         natural language for these attributes is different than what a
         client requests, then they must be reported using the Natural
         Language Override mechanism.
      3. Some attributes are supplied by the device manufacturer (e.g.,
         the Printer object's "printer-make-and-model" attribute).
         These too can be in any natural language.  If the natural
         language for these attributes is different than what a client
         requests, then they must be reported using the Natural Language
         Override mechanism.
      4. Some attributes are supplied by the operator (e.g., the Job
         object's "job-message-from-operator" attribute). These too can
         be in any natural language.  If the natural language for these
         attributes is different than what a client requests, then they
         must be reported using the Natural Language Override mechanism.
      5. Some attributes are generated by the IPP object (e.g., the Job
         object's "job-state-message" attribute, the Printer object's
         "printer-state-message" attribute, and the "status-message"
         operation attribute).  These attributes can only be in one of
         the "generated-natural-language-supported" natural languages.
         If a client requests some natural language for these attributes
         other than one of the supported values, the IPP object SHOULD





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         respond using the value of the "natural-language-configured"
         attribute (using the Natural Language Override mechanism if
         needed).

   The 'text' and 'name' attributes specified in this version of this
   document (additional ones will be registered according to the
   procedures in Section 6) are:

                    Attributes                            Source

   Operation Attributes:
        job-name (name)                         client
        document-name (name)                    client
        requesting-user-name (name)             client
        status-message (text)                   Job or Printer object
        detailed-status-message (text)          Job or Printer object -
                                                see rule 1
        document-access-error (text)            Job or Printer object -
                                                see rule 1

   Job Template Attributes:
        job-hold-until (keyword | name)         client matches
                                                administrator-configured
        job-hold-until-default (keyword | name) client matches
                                                administrator-configured
        job-hold-until-supported (keyword |     client matches
        name)                                   administrator-configured
        job-sheets (keyword | name)             client matches
                                                administrator-configured
        job-sheets-default (keyword | name)     client matches
                                                administrator-configured
        job-sheets-supported (keyword | name)   client matches
                                                administrator-configured
        media (keyword | name)                  client matches
                                                administrator-configured
        media-default (keyword | name)          client matches
                                                administrator-configured
        media-supported (keyword | name)        client matches
                                                administrator-configured
        media-ready (keyword | name)            client matches
                                                administrator-configured

   Job Description Attributes:
        job-name (name)                         client or Printer object
        job-originating-user-name (name)        Printer object
        job-state-message (text)                Job or Printer object
        output-device-assigned (name(127))      administrator
        job-message-from-operator (text(127))   operator



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        job-detailed-status-messages (1setOf    Job or Printer object -
        text)                                   see rule 1
        job-document-access-errors (1setOf      Job or Printer object -
        text)                                   see rule 1

   Printer Description Attributes:
        printer-name (name(127))                administrator
        printer-location (text(127))            administrator
        printer-info (text(127))                administrator
        printer-make-and-model (text(127))      administrator or
                                                manufacturer
        printer-state-message (text)            Printer object
        printer-message-from-operator           operator
        (text(127))

   Rule 1 - Neither the Printer nor the client localizes these message
   attributes, since they are intended for use by the system
   administrator or other experienced technical persons.

8. Security Considerations

   It is difficult to anticipate the security risks that might exist in
   any given IPP environment. For example, if IPP is used within a given
   corporation over a private network, the risks of exposing document
   data may be low enough that the corporation will choose not to use
   encryption on that data.  However, if the connection between the
   client and the IPP object is over a public network, the client may
   wish to protect the content of the information during transmission
   through the network with encryption.

   Furthermore, the value of the information being printed may vary from
   one IPP environment to the next. Printing payroll checks, for
   example, would have a different value than printing public
   information from a file.  There is also the possibly of denial-of-
   service attacks, but denial-of-service attacks against printing
   resources are not well understood and there is no published
   precedents regarding this scenario.

   Once the authenticated identity of the requester has been supplied to
   the IPP object, the object uses that identity to enforce any
   authorization policy that might be in place.  For example, one site's
   policy might be that only the job owner is allowed to cancel a job.
   The details and mechanisms to set up a particular access control
   policy are not part of IPP/1.1, and must be established via some
   other type of administrative or access control framework.  However,
   there are operation status codes that allow an IPP server to return
   information back to a client about any potential access control
   violations for an IPP object.



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   During a create operation, the client's identity is recorded in the
   Job object in an implementation-defined attribute.  This information
   can be used to verify a client's identity for subsequent operations
   on that Job object in order to enforce any access control policy that
   might be in effect.  See section 8.3 below for more details.

   Since the security levels or the specific threats that an IPP system
   administrator may be concerned with cannot be anticipated, IPP MUST
   be capable of operating with different security mechanisms and
   security policies as required by the individual installation.
   Security policies might vary from very strong, to very weak, to none
   at all, and corresponding security mechanisms will be required.

8.1 Security Scenarios

   The following sections describe specific security attacks for IPP
   environments.  Where examples are provided they should be considered
   illustrative of the environment and not an exhaustive set. Not all of
   these environments will necessarily be addressed in initial
   implementations of IPP.

8.1.1 Client and Server in the Same Security Domain

   This environment is typical of internal networks where traditional
   office workers print the output of personal productivity applications
   on shared work-group printers, or where batch applications print
   their output on large production printers. Although the identity of
   the user may be trusted in this environment, a user might want to
   protect the content of a document against such attacks as
   eavesdropping, replaying or tampering.

8.1.2 Client and Server in Different Security Domains

   Examples of this environment include printing a document created by
   the client on a publicly available printer, such as at a commercial
   print shop; or printing a document remotely on a business associate's
   printer.  This latter operation is functionally equivalent to sending
   the document to the business associate as a facsimile. Printing
   sensitive information on a Printer in a different security domain
   requires strong security measures. In this environment authentication
   of the printer is required as well as protection against unauthorized
   use of print resources. Since the document crosses security domains,
   protection against eavesdropping and document tampering are also
   required. It will also be important in this environment to protect
   Printers against "spamming" and malicious document content.






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8.1.3 Print by Reference

   When the document is not stored on the client, printing can be done
   by reference. That is, the print request can contain a reference, or
   pointer, to the document instead of the actual document itself (see
   sections 3.2.2 and 3.3.2). Standard methods currently do not exist
   for remote entities to "assume" the credentials of a client for
   forwarding requests to a 3rd party. It is anticipated that Print-By-
   Reference will be used to access "public" documents and that
   sophisticated methods for authenticating "proxies" is not specified
   in this document.

8.2 URIs in Operation, Job, and Printer attributes

   The "printer-uri-supported" attribute contains the Printer object's
   URI(s).  Its companion attribute, "uri-security-supported",
   identifies the security mechanism used for each URI listed in the
   "printer-uri-supported" attribute.  For each Printer operation
   request, a client MUST supply only one URI in the "printer-uri"
   operation attribute.  In other words, even though the Printer
   supports more than one URI, the client only interacts with the
   Printer object using one if its URIs.  This duality is not needed for
   Job objects, since the Printer objects is the factory for Job
   objects, and the Printer object will generate the correct URI for new
   Job objects depending on the Printer object's security configuration.

8.3 URIs for each authentication mechanisms

   Each URI has an authentication mechanism associated with it. If the
   URI is the i'th element of "printer-uri-supported", then
   authentication mechanism is the "i th" element of "uri-
   authentication-supported". For a list of possible authentication
   mechanisms, see section 4.4.2.

   The Printer object uses an authentication mechanism to determine the
   name of the user performing an operation. This user is called the
   "authenticated user". The credibility of authentication depends on
   the mechanism that the Printer uses to obtain the user's name. When
   the authentication mechanism is 'none', all authenticated users are
   "anonymous".

   During job creation operations, the Printer initializes the value of
   the "job-originating-user-name" attribute (see section 4.3.6) to be
   the authenticated user. The authenticated user is this case is called
   the "job owner".






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   If an implementation can be configured to support more than one
   authentication mechanism (see section 4.4.2), then it MUST implement
   rules for determining equality of authenticated user names which have
   been authenticated via different authentication mechanisms.  One
   possible policy is that identical names that are authenticated via
   different mechanisms are different.  For example, a user can cancel
   his job only if he uses the same authentication mechanism for both
   Cancel-Job and Print-Job.  Another policy is that identical names
   that are authenticated via different mechanism are the same if the
   authentication mechanism for the later operation is not less strong
   than the authentication mechanism for the earlier job creation
   operation.  For example, a user can cancel his job only if he uses
   the same or stronger authentication mechanism for Cancel-Job and
   Print-Job. With this second policy a job submitted via 'requesting-
   user-name' authentication could be canceled via 'digest'
   authentication. With the first policy, the job could not be canceled
   in this way.

   A client is able to determine the authentication mechanism used to
   create a job. It is the i'th value of the Printer's "uri-
   authentication-supported" attribute (see section 4.4.2), where i is
   the index of the element of the Printer's "printer-uri-supported"
   attribute (see section 4.4.1) equal to the job's "job-printer-uri"
   attribute (see section 4.3.3).

8.4 Restricted Queries

   In many IPP operations, a client supplies a list of attributes to be
   returned in the response.  For security reasons, an IPP object may be
   configured not to return all attributes (or all values) that a client
   requests.  The job attributes returned MAY depend on whether the
   requesting user is the same as the user that submitted the job. The
   IPP object MAY even return none of the requested attributes. In such
   cases, the status returned is the same as if the object had returned
   all requested attributes.  The client cannot tell by such a response
   whether the requested attribute was present or absent on the object.

8.5 Operations performed by operators and system administrators

   For the three printer operations Pause-Printer, Resume-Printer, and
   Purge-Jobs (see sections 3.2.7, 3.2.8 and 3.2.9), the requesting user
   is intended to be an operator or administrator of the Printer object
   (see section 1).  Otherwise, the IPP Printer MUST reject the
   operation and return:  'client-error-forbidden', 'client-error-not-
   authenticated', or 'client-error-not-authorized' as appropriate.  For
   operations on jobs, the requesting user is intended to be the job





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   owner or may be an operator or administrator of the Printer object.
   The means for authorizing an operator or administrator of the Printer
   object are not specified in this document.

8.6 Queries on jobs submitted using non-IPP protocols

   If the device that an IPP Printer is representing is able to accept
   jobs using other job submission protocols in addition to IPP, it is
   RECOMMENDED that such an implementation at least allow such "foreign"
   jobs to be queried using Get-Jobs returning "job-id" and "job-uri" as
   'unknown'.  Such an implementation NEED NOT support all of the same
   IPP job attributes as for IPP jobs.  The IPP object returns the
   'unknown' out-of-band value for any requested attribute of a foreign
   job that is supported for IPP jobs, but not for foreign jobs.

   It is further RECOMMENDED, that the IPP Printer generate "job-id" and
   "job-uri" values for such "foreign jobs", if possible, so that they
   may be targets of other IPP operations, such as Get-Job-Attributes
   and Cancel-Job.  Such an implementation also needs to deal with the
   problem of authentication of such foreign jobs.  One approach would
   be to treat all such foreign jobs as belonging to users other than
   the user of the IPP client.  Another approach would be for the
   foreign job to belong to 'anonymous'.  Only if the IPP client has
   been authenticated as an operator or administrator of the IPP Printer
   object, could the foreign jobs be queried by an IPP request.
   Alternatively, if the security policy is to allow users to query
   other users' jobs, then the foreign jobs would also be visible to an
   end-user IPP client using Get-Jobs and Get-Job-Attributes.

9. References

   [ASME-Y14.1M] Metric Drawing Sheet Size and Format, ASME Y14.1M-1995.
                 This standard defines metric sheet sizes and formats
                 for engineering drawings.

   [ASCII]       Coded Character Set - 7-bit American Standard Code for
                 Information Interchange (ASCII), ANSI X3.4-1986. This
                 standard is the specification of the US-ASCII charset.

   [BCP-11]      Bradner S. and R. Hovey, "The Organizations Involved in
                 the IETF Standards Process", BCP 11, RFC 2028, October
                 1996.

   [HTPP]        J. Barnett, K. Carter, R. DeBry,  "Initial Draft -
                 Hypertext Printing Protocol - HTPP/1.0", October 1996,
              ftp://ftp.pwg.org/pub/pwg/ipp/historic/htpp/overview.ps.gz





Hastings, et al.            Standards Track                   [Page 162]

RFC 2911              IPP/1.1: Model and Semantics        September 2000


   [IANA-CON]    Narten, T. and H. Alvestrand, "Guidelines for Writing
                 an IANA Considerations Section in RFCs", BCP 26, RFC
                 2434, October 1998.

   [IANA-CS]     IANA Registry of Coded Character Sets:
                 ftp://ftp.isi.edu/in-notes/iana/assignments/character-
                 sets

   [IANA-MT]     IANA Registry of Media Types:  ftp://ftp.isi.edu/in-
                 notes/iana/assignments/media-types/

   [IPP-IIG]     Hastings, T., Manros, C., Kugler, C., Holst, H., and P.
                 Zehler, "Internet Printing Protocol/1.1:  draft-ietf-
                 ipp-implementers-guide-v11-01.txt, work in progress,
                 May 30, 2000.

   [ISO10646-1]  ISO/IEC 10646-1:1993, "Information technology --
                 Universal Multiple-Octet Coded Character Set (UCS) -
                 Part 1: Architecture and Basic Multilingual Plane,
                 JTC1/SC2."

   [ISO8859-1]   ISO/IEC 8859-1:1987, "Information technology -- 8-bit
                 One-Byte Coded Character Set - Part 1: Latin Alphabet
                 Nr 1", 1987, JTC1/SC2.

   [ISO10175]    ISO/IEC 10175 Document Printing Application (DPA), June
                 1996.

   [LDPA]        T. Hastings,  S. Isaacson,  M. MacKay, C. Manros, D.
                 Taylor, P. Zehler,  "LDPA - Lightweight Document
                 Printing Application", October 1996,
              ftp://ftp.pwg.org/pub/pwg/ipp/historic/ldpa/ldpa8.pdf.gz

   [P1387.4]     Kirk, M. (editor), POSIX System Administration - Part
                 4:  Printing Interfaces, POSIX 1387.4 D8, 1994.

   [PSIS]        Herriot, R. (editor), X/Open A Printing System
                 Interoperability Specification (PSIS), August 1995.

   [PWG]         Printer Working Group, http://www.pwg.org.

   [RFC1035]     Mockapetris, P., "Domain Names - Implementation and
                 Specification", STD 13, RFC 1035, November 1987.

   [RFC1179]     McLaughlin, L., "Line Printer Daemon Protocol", RFC
                 1179, August 1990.





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   [RFC1759]     Smith, R., Wright, F., Hastings, T., Zilles, S. and J.
                 Gyllenskog, "Printer MIB", RFC 1759, March 1995.

   [RFC1766]     Alvestrand, H., "Tags for the Identification of
                 Languages", RFC 1766, March 1995.

   [RFC1951]     Deutsch, P., "DEFLATE Compressed Data Format
                 Specification version 1.3 ", RFC 1951, May 1996.

   [RFC1952]     Deutsch, P., "GZIP file format specification version
                 4.3", RFC 1952, May 1996.

   [RFC1977]     Schryver, V., "PPP BSD Compression Protocol", RFC 1977,
                 August 1996.

   [RFC2026]     Bradner, S., "The Internet Standards Process --
                 Revision 3", BCP 9, RFC 2026, October 1996.

   [RFC2045]     Freed, N. and  N. Borenstein, ", Multipurpose Internet
                 Mail Extensions (MIME) Part One: Format of Internet
                 Message Bodies", RFC 2045, November 1996.

   [RFC2046]     Freed, N. and N. Borenstein, "Multipurpose Internet
                 Mail Extensions (MIME) Part Two: Media Types", RFC
                 2046, November 1996.

   [RFC2048]     Freed, N., Klensin, J. and J. Postel, "Multipurpose
                 Internet Mail Extension (MIME) Part Four: Registration
                 Procedures", RFC 2048, November 1996.

   [RFC2119]     Bradner, S., "Key words for use in RFCs to Indicate
                 Requirement Levels", BCP 14, RFC 2119, March 1997.

   [RFC2228]     Horowitz, M. and S. Lunt, "FTP Security Extensions",
                 RFC 2228, October 1997.

   [RFC2246]     Dierks, T. and C. Allen, "The TLS Protocol Version
                 1.0", RFC 2246, January 1999.

   [RFC2277]     Alvestrand, H., "IETF Policy on Character Sets and
                 Languages" BCP 18, RFC 2277, January 1998.

   [RFC2278]     Freed, N. and J. Postel: "IANA CharSet Registration
                 Procedures", BCP 19, RFC 2278, January 1998.

   [RFC2279]     Yergeau, F., "UTF-8, a transformation format of ISO
                 10646", RFC 2279, January 1998.




Hastings, et al.            Standards Track                   [Page 164]

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   [RFC2316]     Bellovin, S., "Report of the IAB Security Architecture
                 Workshop", RFC 2316, April 1998.

   [RFC2396]     Berners-Lee, T., Fielding, R. and L. Masinter, "Uniform
                 Resource Identifiers (URI): Generic Syntax", RFC 2396,
                 August 1998.

   [RFC2565]     Herriot, R., Butler, S., Moore, P. and R. Turner,
                 "Internet Printing Protocol/1.0: Encoding and
                 Transport", RFC 2565, April 1999.

   [RFC2566]     deBry, R., Hastings, T., Herriot, R., Isaacson, S. and
                 P. Powell, "Internet Printing Protocol/1.0: Model and
                 Semantics", RFC 2566, April 1999.

   [RFC2567]     Wright, D., "Design Goals for an Internet Printing
                 Protocol", RFC 2567, April 1999.

   [RFC2568]     Zilles, S., "Rationale for the Structure and Model and
                 Protocol for the Internet Printing Protocol", RFC 2568,
                 April 1999.

   [RFC2569]     Herriot, R., Hastings, T., Jacobs, N. and J. Martin,
                 "Mapping between LPD and IPP Protocols", RFC 2569,
                 April 1999.

   [RFC2579]     McCloghrie, K., Perkins, D. and J. Schoenwaelder,
                 "Textual Conventions for SMIv2", STD 58, RFC 2579,
                 April 1999.

   [RFC2616]     Fielding, R., Gettys, J., Mogul, J., Frystyk, H.,
                 Masinter, L., Leach, P. and T. Berners-Lee, "Hypertext
                 Transfer Protocol - HTTP/1.1", RFC 2616, June 1999.

   [RFC2617]     Franks, J., Hallam-Baker, P., Hostetler, J., Lawrence,
                 S., Leach, P., Luotonen, A. and L. Stewart, "HTTP
                 Authentication:  Basic and Digest Access
                 Authentication", RFC 2617, June 1999.

   [RFC2639]     Hastings, T. and C. Manros, "Internet Printing
                 Protocol/1.0: Encoding and Transport", RFC 2639, July
                 1999.

   [RFC2910]     Herriot, R., Butler, S., Moore, P., Turner, R. and J.
                 Wenn, "Internet Printing Protocol/1.1: Encoding and
                 Transport", RFC 2910, September 2000.





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   [SSL]         Netscape, The SSL Protocol, Version 3, (Text version
                 3.02), November 1996.

   [SWP]         P. Moore, B. Jahromi, S. Butler, "Simple Web Printing
                 SWP/1.0", May 7, 1997,
                 ftp://ftp.pwg.org/pub/pwg/ipp/new_PRO/swp9705.pdf

10. Authors' Addresses

   Scott A. Isaacson, Editor
   Novell, Inc.
   122 E 1700 S
   Provo, UT   84606

   Phone: 801-861-7366
   Fax:   801-861-2517
   EMail: sisaacson@novell.com


   Tom Hastings
   Xerox Corporation
   737 Hawaii St.  ESAE 231
   El Segundo, CA   90245

   Phone: 310-333-6413
   Fax:   310-333-5514
   EMail: hastings@cp10.es.xerox.com


   Robert Herriot
   Xerox Corp.
   3400 Hill View Ave, Building 1
   Palo Alto, CA 94304

   Phone: 650-813-7696
   Fax:  650-813-6860
   EMail: robert.herriot@pahv.xerox.com


   Roger deBry
   Utah Valley State College
   Orem, UT 84058

   Phone: (801) 222-8000
   EMail: debryro@uvsc.edu






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   Patrick Powell
   Astart Technologies
   9475 Chesapeake Dr., Suite D
   San Diego, CA  95123

   Phone: (619) 874-6543
   Fax:   (619) 279-8424
   EMail: papowell@astart.com

   IPP Web Page:  http://www.pwg.org/ipp/
   IPP Mailing List:  ipp@pwg.org

   To subscribe to the ipp mailing list, send the following email:
      1) send it to majordomo@pwg.org
      2) leave the subject line blank
      3) put the following two lines in the message body:
            subscribe ipp
            end

   Implementers of this specification document are encouraged to join
   IPP Mailing List in order to participate in any discussions of
   clarification issues and review of registration proposals for
   additional attributes and values.

   Other Participants:

   Chuck Adams - Tektronix             Shivaun Albright - HP
   Stefan Andersson - Axis             Jeff Barnett - IBM
   Ron Bergman - Hitachi Koki Imaging  Dennis Carney - IBM
   Systems
   Keith Carter - IBM                  Angelo Caruso - Xerox
   Rajesh Chawla - TR Computing        Nancy Chen - Okidata
   Solutions
   Josh Cohen - Microsoft              Jeff Copeland - QMS
   Andy Davidson - Tektronix           Roger deBry - IBM
   Maulik Desai - Auco                 Mabry Dozier - QMS
   Lee Farrell - Canon Information     Satoshi Fujitami - Ricoh
   Systems
   Steve Gebert - IBM                  Sue Gleeson - Digital
   Charles Gordon - Osicom             Brian Grimshaw - Apple
   Jerry Hadsell - IBM                 Richard Hart - Digital
   Tom Hastings - Xerox                Henrik Holst - I-data
   Stephen Holmstead                   Zhi-Hong Huang - Zenographics
   Scott Isaacson - Novell             Babek Jahromi - Microsoft
   Swen Johnson - Xerox                David Kellerman - Northlake
                                       Software
   Robert Kline - TrueSpectra          Charles Kong - Panasonic
   Carl Kugler - IBM                   Dave Kuntz - Hewlett-Packard



Hastings, et al.            Standards Track                   [Page 167]

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   Takami Kurono - Brother             Rick Landau - Digital
   Scott Lawrence - Agranot Systems    Greg LeClair - Epson
   Dwight Lewis - Lexmark              Harry Lewis - IBM
   Tony Liao - Vivid Image             Roy Lomicka - Digital
   Pete Loya - HP                      Ray Lutz - Cognisys
   Mike MacKay - Novell, Inc.          David Manchala - Xerox
   Carl-Uno Manros - Xerox             Jay Martin - Underscore
   Stan McConnell - Xerox              Larry Masinter - Xerox
   Sandra Matts - Hewlett Packard      Peter Michalek - Shinesoft
   Ira McDonald - High North Inc.      Mike Moldovan - G3 Nova
   Tetsuya Morita - Ricoh              Yuichi Niwa - Ricoh
   Pat Nogay - IBM                     Ron Norton - Printronics
   Hugo Parra, Novell                  Bob Pentecost - Hewlett-Packard
   Patrick Powell - Astart             Jeff Rackowitz - Intermec
   Technologies
   Eric Random - Peerless              Rob Rhoads - Intel
   Xavier Riley - Xerox                Gary Roberts - Ricoh
   David Roach - Unisys                Stuart Rowley - Kyocera
   Yuji Sasaki - Japan Computer        Richard Schneider - Epson
   Industry
   Kris Schoff - HP                    Katsuaki Sekiguchi - Canon
   Bob Setterbo - Adobe                Gail Songer - Peerless
   Hideki Tanaka - Cannon              Devon Taylor - Novell
   Mike Timperman - Lexmark            Atsushi Uchino - Epson
   Shigeru Ueda - Canon                Bob Von Andel - Allegro Software
   William Wagner - NetSilicon/DPI     Jim Walker - DAZEL
   Chris Wellens - Interworking Labs   Trevor Wells - Hewlett Packard
   Craig Whittle - Sharp Labs          Rob Whittle - Novell, Inc.
   Jasper Wong - Xionics               Don Wright - Lexmark
   Michael Wu - Heidelberg Digital     Rick Yardumian - Xerox
   Michael Yeung - Toshiba             Lloyd Young - Lexmark
   Atsushi Yuki - Kyocera              Peter Zehler - Xerox
   William Zhang- Canon Information    Frank Zhao - Panasonic
   Systems
   Steve Zilles - Adobe                Rob Zirnstein - Canon Information
                                       Systems

11. Formats for IPP Registration Proposals

   In order to propose an IPP extension for registration, the proposer
   must submit an application to IANA by email to "iana@iana.org" or by
   filling out the appropriate form on the IANA web pages
   (http://www.iana.org).  This section specifies the required
   information and the formats for proposing registrations of extensions
   to IPP as provided in Section 6 for:






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      1. type2 'keyword' attribute values
      2. type3 'keyword' attribute values
      3. type2 'enum' attribute values
      4. type3 'enum' attribute values
      5. attributes
      6. attribute syntaxes
      7. operations
      8. status codes
      9. out-of-band attribute values

11.1 Type2 keyword attribute values registration,

   Type of registration:  type2 keyword attribute value
   Name of attribute to which this keyword specification is to be added:
   Proposed keyword name of this keyword value:
   Specification of this keyword value (follow the style of IPP Model
   Section 4.1.2.3):
   Name of proposer:
   Address of proposer:
   Email address of proposer:

   Note:  For type2 keywords, the Designated Expert will be the point of
   contact for the approved registration specification, if any
   maintenance of the registration specification is needed.

11.2 Type3 keyword attribute values registration

   Type of registration:  type3 keyword attribute value
   Name of attribute to which this keyword specification is to be added:
   Proposed keyword name of this keyword value:
   Specification of this keyword value (follow the style of IPP Model
   Section 4.1.2.3):
   Name of proposer:
   Address of proposer:
   Email address of proposer:

   Note:  For type3 keywords, the proposer will be the point of contact
   for the approved registration specification, if any maintenance of
   the registration specification is needed.

11.3 Type2 enum attribute values registration

   Type of registration:  type2 enum attribute value
   Name of attribute to which this enum specification is to be added:
   Keyword symbolic name of this enum value:
   Numeric value (to be assigned by the IPP Designated Expert in
   consultation with IANA):




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   Specification of this enum value (follow the style of IPP Model
   Section 4.1.4):
   Name of proposer:
   Address of proposer:
   Email address of proposer:

   Note:  For type2 enums, the Designated Expert will be the point of
   contact for the approved registration specification, if any
   maintenance of the registration specification is needed.

11.4 Type3 enum attribute values registration

   Type of registration:  type3 enum attribute value
   Name of attribute to which this enum specification is to be added:
   Keyword symbolic name of this enum value:
   Numeric value (to be assigned by the IPP Designated Expert in
   consultation with IANA):
   Specification of this enum value (follow the style of IPP Model
   Section 4.1.4):
   Name of proposer:
   Address of proposer:
   Email address of proposer:

   Note:  For type3 enums, the proposer will be the point of contact for
   the approved registration specification, if any maintenance of the
   registration specification is needed.

11.5 Attribute registration

   Type of registration:  attribute
   Proposed keyword name of this attribute:
   Types of attribute (Operation, Job Template, Job Description, Printer
   Description):
   Operations to be used with if the attribute is an operation attribute:
   Object (Job, Printer, etc. if bound to an object):
   Attribute syntax(es) (include 1setOf and range as in Section 4.2):
   If attribute syntax is 'keyword' or 'enum', is it type2 or type3:
   If this is a Printer attribute, MAY the value returned depend on
   "document-format" (See Section 6.2):
   If this is a Job Template attribute, how does its specification depend
   on the value of the "multiple-document-handling" attribute:
   Specification of this attribute (follow the style of IPP Model Section
   4.2):
   Name of proposer:
   Address of proposer:
   Email address of proposer:





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   Note:  For attributes, the IPP Designated Expert will be the point of
   contact for the approved registration specification, if any
   maintenance of the registration specification is needed.

11.6 Attribute Syntax registration

   Type of registration:  attribute syntax
   Proposed name of this attribute syntax:
   Type of attribute syntax (integer, octetString, character-string,  see
   [RFC2910]):
   Numeric tag according to [RFC2910] (to be assigned by the IPP
   Designated Expert in consultation with IANA):
   Specification of this attribute (follow the style of IPP Model Section
   4.1):
   Name of proposer:
   Address of proposer:
   Email address of proposer:

   Note:  For attribute syntaxes, the IPP Designated Expert will be the
   point of contact for the approved registration specification, if any
   maintenance of the registration specification is needed.

11.7 Operation registration

   Type of registration:  operation
   Proposed name of this operation:
   Numeric operation-id value according to section 4.4.15 (to be assigned
   by the IPP Designated Expert in consultation with IANA):
   Object Target (Job, Printer, etc. that operation is upon):
   Specification of this operation (follow the style of IPP Model Section
   3):
   Name of proposer:
   Address of proposer:
   Email address of proposer:

   Note:  For operations, the IPP Designated Expert will be the point of
   contact for the approved registration specification, if any
   maintenance of the registration specification is needed.

11.8 Attribute Group registration

   Type of registration:  attribute group
   Proposed name of this attribute group:
   Numeric tag according to [RFC2910] (to be assigned by the IPP
   Designated Expert in consultation with IANA):
   Operation requests and group number for each operation in which the
   attribute group occurs:




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   Operation responses and group number for each operation in which the
   attribute group occurs:
   Specification of this attribute group (follow the style of IPP Model
   Section 3):
   Name of proposer:
   Address of proposer:
   Email address of proposer:

   Note:  For attribute groups, the IPP Designated Expert will be the
   point of contact for the approved registration specification, if any
   maintenance of the registration specification is needed.

11.9 Status code registration

   Type of registration:  status code
   Keyword symbolic name of this status code value:
   Numeric value (to be assigned by the IPP Designated Expert in
   consultation with IANA):
   Operations that this status code may be used with:
   Specification of this status code (follow the style of IPP Model
   Section 13 APPENDIX B:  Status Codes and Suggested Status Code
   Messages):
   Name of proposer:
   Address of proposer:
   Email address of proposer:

   Note:  For status codes, the Designated Expert will be the point of
   contact for the approved registration specification, if any
   maintenance of the registration specification is needed.

11.10 Out-of-band Attribute Value registration

   Type of registration:  out-of-band attribute value
   Proposed name of this out-of-band attribute value:
   Numeric tag according to [RFC2910] (to be assigned by the IPP Designated
   Expert in consultation with IANA):
   Operations that this out-of-band attribute value may be used with:
   Attributes that this out-of-band attribute value may be used with:
   Specification of this out-of-band attribute value (follow the style of
   the beginning of IPP Model Section 4.1):
   Name of proposer:
   Address of proposer:
   Email address of proposer:

   Note:  For out-of-band attribute values, the IPP Designated Expert
   will be the point of contact for the approved registration
   specification, if any maintenance of the registration specification
   is needed.



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12. APPENDIX A: Terminology

   This specification document uses the terminology defined in this
   section.

12.1 Conformance Terminology

   The key words "MUST", "MUST NOT", "REQUIRED", "SHOULD", "SHOULD NOT",
   "RECOMMENDED", "MAY", and  "OPTIONAL" in this document are to be
   interpreted as described in RFC 2119 [RFC2119].

12.1.1 NEED NOT

   This term is not included in RFC 2119.  The verb "NEED NOT" indicates
   an action that the subject of the sentence does not have to implement
   in order to claim conformance to the standard.  The verb "NEED NOT"
   is used instead of "MAY NOT" since "MAY NOT" sounds like a
   prohibition.

12.2 Model Terminology

12.2.1 Keyword

   Keywords are used within this document as identifiers of semantic
   entities within the abstract model (see section 4.1.2.3).  Attribute
   names, some attribute values, attribute syntaxes, and attribute group
   names are represented as keywords.

12.2.2 Attributes

   An attribute is an item of information that is associated with an
   instance of an IPP object.  An attribute consists of an attribute
   name and one or more attribute values.  Each attribute has a specific
   attribute syntax.  All object attributes are defined in section 4 and
   all operation attributes are defined in section 3.

   Job Template Attributes are described in section 4.2. The client
   optionally supplies Job Template attributes in a create request
   (operation requests that create Job objects).  The Printer object has
   associated attributes which define supported and default values for
   the Printer.

12.2.2.1 Attribute Name

   Each attribute is uniquely identified in this document by its
   attribute name.  An attribute name is a keyword.  The keyword
   attribute name is given in the section header describing that




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   attribute.  In running text in this document, attribute names are
   indicated inside double quotation marks (") where the quotation marks
   are not part of the keyword itself.

12.2.2.2 Attribute Group Name

   Related attributes are grouped into named groups.  The name of the
   group is a keyword.  The group name may be used in place of naming
   all the attributes in the group explicitly.  Attribute groups are
   defined in section 3.

12.2.2.3 Attribute Value

   Each attribute has one or more values.  Attribute values are
   represented in the syntax type specified for that attribute. In
   running text in this document, attribute values are indicated inside
   single quotation marks ('), whether their attribute syntax is
   keyword, integer, text, etc.  where the quotation marks are not part
   of the value itself.

12.2.2.4 Attribute Syntax

   Each attribute is defined using an explicit syntax type.  In this
   document, each syntax type is defined as a keyword with specific
   meaning.  The "Encoding and Transport" document [RFC2910] indicates
   the actual "on-the-wire" encoding rules for each syntax type.
   Attribute syntax types are defined in section 4.1.

12.2.3 Supports

   By definition, a Printer object supports an attribute only if that
   Printer object responds with the corresponding attribute populated
   with some value(s) in a response to a query for that attribute.  A
   Printer object supports an attribute value if the value is one of the
   Printer object's "supported values" attributes.  The device behind a
   Printer object may exhibit a behavior that corresponds to some IPP
   attribute, but if the Printer object, when queried for that
   attribute, doesn't respond with the attribute, then as far as IPP is
   concerned, that implementation does not support that feature. If the
   Printer object's "xxx-supported" attribute is not populated with a
   particular value (even if that value is a legal value for that
   attribute), then that Printer object does not support that particular
   value.








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   A conforming implementation MUST support all REQUIRED attributes.
   However, even for REQUIRED attributes, conformance to IPP does not
   mandate that all implementations support all possible values
   representing all possible job processing behaviors and features.  For
   example, if a given instance of a Printer supports only certain
   document formats, then that Printer responds with the "document-
   format-supported" attribute populated with a set of values, possibly
   only one, taken from the entire set of possible values defined for
   that attribute. This limited set of values represents the Printer's
   set of supported document formats.  Supporting an attribute and some
   set of values for that attribute enables IPP end users to be aware of
   and make use of those features associated with that attribute and
   those values.  If an implementation chooses to not support an
   attribute or some specific value, then IPP end users would have no
   ability to make use of that feature within the context of IPP itself.
   However, due to existing practice and legacy systems which are not
   IPP aware, there might be some other mechanism outside the scope of
   IPP to control or request the "unsupported" feature (such as embedded
   instructions within the document data itself).

   For example, consider the "finishings-supported" attribute.

      1) If a Printer object is not physically capable of stapling, the
         "finishings-supported" attribute MUST NOT be populated with the
         value of 'staple'.
      2) A Printer object is physically capable of stapling, however an
         implementation chooses not to support stapling in the IPP
         "finishings" attribute.  In this case, 'staple' MUST NOT be a
         value in the "finishings-supported" Printer object attribute.
         Without support for the value 'staple', an IPP end user would
         have no means within the protocol itself to request that a Job
         be stapled.  However, an existing document data formatter might
         be able to request that the document be stapled directly with
         an embedded instruction within the document data.  In this
         case, the IPP implementation does not "support" stapling,
         however the end user is still able to have some control over
         the stapling of the completed job.
      3) A Printer object is physically capable of stapling, and an
         implementation chooses to support stapling in the IPP
         "finishings" attribute. In this case, 'staple' MUST be a value
         in the "finishings-supported" Printer object attribute. Doing
         so, would enable end users to be aware of and make use of the
         stapling feature using IPP attributes.








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   Even though support for Job Template attributes by a Printer object
   is OPTIONAL, it is RECOMMENDED that if the device behind a Printer
   object is capable of realizing any feature or function that
   corresponds to an IPP attribute and some associated value, then that
   implementation SHOULD support that IPP attribute and value.

   The set of values in any of the supported value attributes is set
   (populated) by some administrative process or automatic sensing
   mechanism that is outside the scope of this IPP/1.1 document.  For
   administrative policy and control reasons, an administrator may
   choose to make only a subset of possible values visible to the end
   user.  In this case, the real output device behind the IPP Printer
   abstraction may be capable of a certain feature, however an
   administrator is specifying that access to that feature not be
   exposed to the end user through the IPP protocol.  Also, since a
   Printer object may represent a logical print device (not just a
   physical device) the actual process for supporting a value is
   undefined and left up to the implementation.  However, if a Printer
   object supports a value, some manual human action may be needed to
   realize the semantic action associated with the value, but no end
   user action is required.

   For example, if one of the values in the "finishings-supported"
   attribute is 'staple', the actual process might be an automatic
   staple action by a physical device controlled by some command sent to
   the device.  Or, the actual process of stapling might be a manual
   action by an operator at an operator attended Printer object.

   For another example of how supported attributes function, consider a
   system administrator who desires to control all print jobs so that no
   job sheets are printed in order to conserve paper.  To force no job
   sheets, the system administrator sets the only supported value for
   the "job-sheets-supported" attribute to 'none'.  In this case, if a
   client requests anything except 'none', the create request is
   rejected or the "job-sheets" value is ignored (depending on the value
   of "ipp-attribute-fidelity").  To force the use of job start/end
   sheets on all jobs, the administrator does not include the value
   'none' in the "job-sheets- supported" attribute.  In this case, if a
   client requests 'none', the create request is rejected or the "job-
   sheets" value is ignored (again depending on the value of "ipp-
   attribute-fidelity").

12.2.4 print-stream page

   A "print-stream page" is a page according to the definition of pages
   in the language used to express the document data.





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12.2.5 impression

   An "impression" is the image (possibly many print-stream pages in
   different configurations) imposed onto a single media page.

13. APPENDIX B:  Status Codes and Suggested Status Code Messages

   This section defines status code enum keywords and values that are
   used to provide semantic information on the results of an operation
   request.  Each operation response MUST include a status code.  The
   response MAY also contain a status message that provides a short
   textual description of the status.  The status code is intended for
   use by automata, and the status message is intended for the human end
   user.  Since the status message is an OPTIONAL component of the
   operation response, an IPP application (i.e., a browser, GUI, print
   driver or gateway) is NOT REQUIRED to examine or display the status
   message, since it MAY not be returned to the application.

   The prefix of the status keyword defines the class of response as
   follows:

      "informational" - Request received, continuing process
      "successful" - The action was successfully received, understood,
         and accepted
      "redirection" - Further action must be taken in order to complete
         the request
      "client-error" - The request contains bad syntax or cannot be
         fulfilled
      "server-error" - The IPP object  failed to fulfill an apparently
         valid request

   As with type2 enums, IPP status codes are extensible.  IPP clients
   are NOT REQUIRED to understand the meaning of all registered status
   codes, though such understanding is obviously desirable.  However,
   IPP clients MUST understand the class of any status code, as
   indicated by the prefix, and treat any unrecognized response as being
   equivalent to the first status code of that class, with the exception
   that an unrecognized response MUST NOT be cached.  For example, if an
   unrecognized status code of "client-error-xxx-yyy" is received by the
   client, it can safely assume that there was something wrong with its
   request and treat the response as if it had received a "client-
   error-bad-request" status code.  In such cases, IPP applications
   SHOULD present the OPTIONAL message (if present) to the end user
   since the message is likely to contain human readable information
   which will help to explain the unusual status.  The name of the enum
   is the suggested status message for US English.





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   The status code values range from 0x0000 to 0x7FFF.  The value ranges
   for each status code class are as follows:

      "successful" - 0x0000 to 0x00FF
      "informational" - 0x0100 to 0x01FF
      "redirection" - 0x0200 to 0x02FF
      "client-error" - 0x0400 to 0x04FF
      "server-error" - 0x0500 to 0x05FF

   The top half (128 values) of each range (0x0n40 to 0x0nFF, for n = 0
   to 5) is reserved for vendor use within each status code class.
   Values 0x0600 to 0x7FFF are reserved for future assignment by IETF
   standards track documents and MUST NOT be used.

13.1 Status Codes

   Each status code is described below. Section 13.1.5.9 contains a
   table that indicates which status codes apply to which operations.
   The Implementer's Guide [IPP-IIG] describe the suggested steps for
   processing IPP attributes for all operations, including returning
   status codes.

13.1.1 Informational

   This class of status code indicates a provisional response and is to
   be used for informational purposes only.

   There are no status codes defined in IPP/1.1 for this class of status
   code.

13.1.2 Successful Status Codes

   This class of status code indicates that the client's request was
   successfully received, understood, and accepted.

13.1.2.1 successful-ok (0x0000)

   The request has succeeded and no request attributes were substituted
   or ignored.  In the case of a response to a create request, the
   'successful-ok' status code indicates that the request was
   successfully received and validated, and that the Job object has been
   created; it does not indicate that the job has been processed.  The
   transition of the Job object into the 'completed' state is the only
   indicator that the job has been printed.







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13.1.2.2 successful-ok-ignored-or-substituted-attributes (0x0001)

   The request has succeeded, but some supplied (1) attributes were
   ignored or (2) unsupported values were substituted with supported
   values or were ignored in order to perform the operation without
   rejecting it.  Unsupported attributes, attribute syntaxes, or values
   MUST be returned in the Unsupported Attributes group of the response
   for all operations.  There is an exception to this rule for the query
   operations:  Get-Printer-Attributes, Get-Jobs, and Get-Job-Attributes
   for the "requested-attributes" operation attribute only.  When the
   supplied values of the "requested-attributes" operation attribute are
   requesting attributes that are not supported, the IPP object MAY, but
   is NOT REQUIRED to, return the "requested-attributes" attribute in
   the Unsupported Attribute response group (with the unsupported values
   only).  See sections 3.1.7 and 3.2.1.2.

13.1.2.3 successful-ok-conflicting-attributes (0x0002)

   The request has succeeded, but some supplied attribute values
   conflicted with the values of other supplied attributes.  These
   conflicting values were either (1) substituted with (supported)
   values or (2) the attributes were removed in order to process the job
   without rejecting it.  Attributes or values which conflict with other
   attributes and have been substituted or ignored MUST be returned in
   the Unsupported Attributes group of the response for all operations
   as supplied by the client.  See sections 3.1.7 and 3.2.1.2.

13.1.3 Redirection Status Codes

   This class of status code indicates that further action needs to be
   taken to fulfill the request.

   There are no status codes defined in IPP/1.1 for this class of status
   code.

13.1.4 Client Error Status Codes

   This class of status code is intended for cases in which the client
   seems to have erred.  The IPP object SHOULD return a message
   containing an explanation of the error situation and whether it is a
   temporary or permanent condition.










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13.1.4.1 client-error-bad-request (0x0400)

   The request could not be understood by the IPP object due to
   malformed syntax (such as the value of a fixed length attribute whose
   length does not match the prescribed length for that attribute - see
   the Implementer's Guide [IPP-IIG] ).  The IPP application SHOULD NOT
   repeat the request without modifications.

13.1.4.2 client-error-forbidden (0x0401)

   The IPP object understood the request, but is refusing to fulfill it.
   Additional authentication information or authorization credentials
   will not help and the request SHOULD NOT be repeated.  This status
   code is commonly used when the IPP object does not wish to reveal
   exactly why the request has been refused or when no other response is
   applicable.

13.1.4.3 client-error-not-authenticated (0x0402)

   The request requires user authentication.  The IPP client may repeat
   the request with suitable authentication information. If the request
   already included authentication information, then this status code
   indicates that authorization has been refused for those credentials.
   If this response contains the same challenge as the prior response,
   and the user agent has already attempted authentication at least
   once, then the response message may contain relevant diagnostic
   information.  This status codes reveals more information than
   "client-error-forbidden".

13.1.4.4 client-error-not-authorized (0x0403)

   The requester is not authorized to perform the request.  Additional
   authentication information or authorization credentials will not help
   and the request SHOULD NOT be repeated.  This status code is used
   when the IPP object wishes to reveal that the authentication
   information is understandable, however, the requester is explicitly
   not authorized to perform the request.  This status codes reveals
   more information than "client-error-forbidden" and "client-error-
   not-authenticated".

13.1.4.5 client-error-not-possible (0x0404)

   This status code is used when the request is for something that can
   not happen.  For example, there might be a request to cancel a job
   that has already been canceled or aborted by the system.  The IPP
   client SHOULD NOT repeat the request.





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13.1.4.6 client-error-timeout (0x0405)

   The client did not produce a request within the time that the IPP
   object was prepared to wait.  For example, a client issued a Create-
   Job operation and then, after a long period of time, issued a Send-
   Document operation and this error status code was returned in
   response to the Send-Document request  (see section 3.3.1).  The IPP
   object might have been forced to clean up resources that had been
   held for the waiting additional Documents.  The IPP object was forced
   to close the Job since the client took too long.  The client SHOULD
   NOT repeat the request without modifications.

13.1.4.7 client-error-not-found (0x0406)

   The IPP object has not found anything matching the request URI.  No
   indication is given of whether the condition is temporary or
   permanent.  For example, a client with an old reference to a Job (a
   URI) tries to cancel the Job, however in the mean time the Job might
   have been completed and all record of it at the Printer has been
   deleted.  This status code, 'client-error-not-found' is returned
   indicating that the referenced Job can not be found.  This error
   status code is also used when a client supplies a URI as a reference
   to the document data in either a Print-URI or Send-URI operation, but
   the document can not be found.

   In practice, an IPP application should avoid a not found situation by
   first querying and presenting a list of valid Printer URIs and Job
   URIs to the end-user.

13.1.4.8 client-error-gone (0x0407)

   The requested object is no longer available and no forwarding address
   is known.  This condition should be considered permanent.  Clients
   with link editing capabilities should delete references to the
   request URI after user approval.  If the IPP object does not know or
   has no facility to determine, whether or not the condition is
   permanent, the status code "client-error-not-found" should be used
   instead.

   This response is primarily intended to assist the task of maintenance
   by notifying the recipient that the resource is intentionally
   unavailable and that the IPP object administrator desires that remote
   links to that resource be removed. It is not necessary to mark all
   permanently unavailable resources as "gone" or to keep the mark for
   any length of time -- that is left to the discretion of the IPP
   object administrator and/or Printer implementation.





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13.1.4.9 client-error-request-entity-too-large (0x0408)

   The IPP object is refusing to process a request because the request
   entity is larger than the IPP object is willing or able to process.
   An IPP Printer returns this status code when it limits the size of
   print jobs and it receives a print job that exceeds that limit or
   when the attributes are so many that their encoding causes the
   request entity to exceed IPP object capacity.

13.1.4.10 client-error-request-value-too-long (0x0409)

   The IPP object is refusing to service the request because one or more
   of the client-supplied attributes has a variable length value that is
   longer than the maximum length specified for that attribute.  The IPP
   object might not have sufficient resources (memory, buffers, etc.) to
   process (even temporarily), interpret, and/or ignore a value larger
   than the maximum length.  Another use of this error code is when the
   IPP object supports the processing of a large value that is less than
   the maximum length, but during the processing of the request as a
   whole, the object may pass the value onto some other system component
   which is not able to accept the large value.  For more details, see
   the Implementer's Guide [IPP-IIG] .

   Note:  For attribute values that are URIs, this rare condition is
   only likely to occur when a client has improperly submitted a request
   with long query information (e.g. an IPP application allows an end-
   user to enter an invalid URI), when the client has descended into a
   URI "black hole" of redirection (e.g., a redirected URI prefix that
   points to a suffix of itself), or when the IPP object is under attack
   by a client attempting to exploit security holes present in some IPP
   objects using fixed-length buffers for reading or manipulating the
   Request-URI.

13.1.4.11 client-error-document-format-not-supported (0x040A)

   The IPP object is refusing to service the request because the
   document data is in a format, as specified in the "document-format"
   operation attribute, that is not supported by the Printer object.
   This error is returned independent of the client-supplied "ipp-
   attribute-fidelity".  The Printer object MUST return this status
   code, even if there are other Job Template attributes that are not
   supported as well, since this error is a bigger problem than with Job
   Template attributes.  See sections 3.1.6.1, 3.1.7, and 3.2.1.1.








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13.1.4.12 client-error-attributes-or-values-not-supported (0x040B)

   In a create request, if the Printer object does not support one or
   more attributes, attribute syntaxes, or attribute values supplied in
   the request and the client supplied the "ipp-attribute-fidelity"
   operation attribute with the 'true' value, the Printer object MUST
   return this status code.  The Printer object MUST also return in the
   Unsupported Attributes Group all the attributes and/or values
   supplied by the client that are not supported.  See section 3.1.7.
   For example, if the request indicates 'iso-a4' media, but that media
   type is not supported by the Printer object.  Or, if the client
   supplies a Job Template attribute and the attribute itself is not
   even supported by the Printer.  If the "ipp-attribute-fidelity"
   attribute is 'false', the Printer MUST ignore or substitute values
   for unsupported Job Template attributes and values rather than reject
   the request and return this status code.

   For any operation where a client requests attributes (such as a Get-
   Jobs, Get-Printer-Attributes, or Get-Job-Attributes operation), if
   the IPP object does not support one or more of the requested
   attributes, the IPP object simply ignores the unsupported requested
   attributes and processes the request as if they had not been
   supplied, rather than returning this status code.  In this case, the
   IPP object MUST return the 'successful-ok-ignored-or-substituted-
   attributes' status code and MAY return the unsupported attributes as
   values of the "requested-attributes" in the Unsupported Attributes
   Group (see section 13.1.2.2).

13.1.4.13 client-error-uri-scheme-not-supported (0x040C)

   The scheme of the client-supplied URI in a Print-URI or a Send-URI
   operation is not supported.  See sections 3.1.6.1 and 3.1.7.

13.1.4.14 client-error-charset-not-supported (0x040D)

   For any operation, if the IPP Printer does not support the charset
   supplied by the client in the "attributes-charset" operation
   attribute, the Printer MUST reject the operation and return this
   status and any 'text' or 'name' attributes using the 'utf-8' charset
   (see Section 3.1.4.1).  See sections 3.1.6.1 and  3.1.7.

13.1.4.15 client-error-conflicting-attributes (0x040E)

   The request is rejected because some attribute values conflicted with
   the values of other attributes which this document does not permit to
   be substituted or ignored.  The Printer object MUST also return in
   the Unsupported Attributes Group the conflicting attributes supplied
   by the client.  See sections 3.1.7 and 3.2.1.2.



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13.1.4.16 client-error-compression-not-supported (0x040F)

   The IPP object is refusing to service the request because the
   document data, as specified in the "compression" operation attribute,
   is compressed in a way that is not supported by the Printer object.
   This error is returned independent of the client-supplied "ipp-
   attribute-fidelity".  The Printer object MUST return this status
   code, even if there are other Job Template attributes that are not
   supported as well, since this error is a bigger problem than with Job
   Template attributes.  See sections 3.1.6.1, 3.1.7, and 3.2.1.1.

13.1.4.17 client-error-compression-error (0x0410)

   The IPP object is refusing to service the request because the
   document data cannot be decompressed when using the algorithm
   specified by the "compression" operation attribute.  This error is
   returned independent of the client-supplied "ipp-attribute-fidelity".
   The Printer object MUST return this status code, even if there are
   Job Template attributes that are not supported as well, since this
   error is a bigger problem than with Job Template attributes.  See
   sections 3.1.7 and 3.2.1.1.

13.1.4.18 client-error-document-format-error (0x0411)

   The IPP object is refusing to service the request because Printer
   encountered an error in the document data while interpreting it.
   This error is returned independent of the client-supplied "ipp-
   attribute-fidelity".  The Printer object MUST return this status
   code, even if there are Job Template attributes that are not
   supported as well, since this error is a bigger problem than with Job
   Template attributes.  See sections 3.1.7 and 3.2.1.1.

13.1.4.19 client-error-document-access-error (0x0412)

   The IPP object is refusing to service the Print-URI or Send-URI
   request because Printer encountered an access error while attempting
   to validate the accessibility or access the document data specified
   in the "document-uri" operation attribute.  The Printer MAY also
   return a specific document access error code using the "document-
   access-error" operation attribute (see section 3.1.6.4).  This error
   is returned independent of the client-supplied "ipp-attribute-
   fidelity".  The Printer object MUST return this status code, even if
   there are Job Template attributes that are not supported as well,
   since this error is a bigger problem than with Job Template
   attributes.  See sections 3.1.6.1 and 3.1.7.






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13.1.5 Server Error Status Codes

   This class of status codes indicates cases in which the IPP object is
   aware that it has erred or is incapable of performing the request.
   The IPP object SHOULD include a message containing an explanation of
   the error situation, and whether it is a temporary or permanent
   condition.

13.1.5.1 server-error-internal-error (0x0500)

   The IPP object encountered an unexpected condition that prevented it
   from fulfilling the request.  This error status code differs from
   "server-error-temporary-error" in that it implies a more permanent
   type of internal error.  It also differs from "server-error-device-
   error" in that it implies an unexpected condition (unlike a paper-jam
   or out-of-toner problem which is undesirable but expected).  This
   error status code indicates that probably some knowledgeable human
   intervention is required.

13.1.5.2 server-error-operation-not-supported (0x0501)

   The IPP object does not support the functionality required to fulfill
   the request. This is the appropriate response when the IPP object
   does not recognize an operation or is not capable of supporting it.
   See sections 3.1.6.1 and 3.1.7.

13.1.5.3 server-error-service-unavailable (0x0502)

   The IPP object is currently unable to handle the request due to a
   temporary overloading or maintenance of the IPP object.  The
   implication is that this is a temporary condition which will be
   alleviated after some delay. If known, the length of the delay may be
   indicated in the message.  If no delay is given, the IPP application
   should handle the response as it would for a "server-error-
   temporary-error" response.  If the condition is more permanent, the
   error status codes "client-error-gone" or "client-error-not-found"
   could be used.

13.1.5.4 server-error-version-not-supported (0x0503)

   The IPP object does not support, or refuses to support, the IPP
   protocol version that was supplied as the value of the "version-
   number" operation parameter in the request.  The IPP object is
   indicating that it is unable or unwilling to complete the request
   using the same major and minor version number as supplied in the
   request other than with this error message. The error response SHOULD
   contain a "status-message" attribute (see section 3.1.6.2) describing




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   why that version is not supported and what other versions are
   supported by that IPP object.  See sections 3.1.6.1, 3.1.7, and
   3.1.8.

   The error response MUST identify in the "version-number" operation
   parameter the closest version number that the IPP object does
   support.  For example, if a client supplies version '1.0' and an
   IPP/1.1 object supports version '1.0', then it responds with version
   '1.0' in all responses to such a request.  If the IPP/1.1 object does
   not support version '1.0', then it should accept the request and
   respond with version '1.1' or may reject the request and respond with
   this error code and version
   '1.1'.  If a client supplies a version '1.2', the IPP/1.1 object
   should accept the request and return version '1.1' or may reject the
   request and respond with this error code and version '1.1'.  See
   sections 3.1.8 and 4.4.14.

13.1.5.5 server-error-device-error (0x0504)

   A printer error, such as a paper jam, occurs while the IPP object
   processes a Print or Send operation.  The response contains the true
   Job Status (the values of the "job-state" and "job-state-reasons"
   attributes).  Additional information can be returned in the OPTIONAL
   "job-state-message" attribute value or in the OPTIONAL status message
   that describes the error in more detail.  This error status code is
   only returned in situations where the Printer is unable to accept the
   create request because of such a device error.  For example, if the
   Printer is unable to spool, and can only accept one job at a time,
   the reason it might reject a create request is that the printer
   currently has a paper jam.  In many cases however, where the Printer
   object can accept the request even though the Printer has some error
   condition, the 'successful-ok' status code will be returned.  In such
   a case, the client would look at the returned Job Object Attributes
   or later query the Printer to determine its state and state reasons.

13.1.5.6 server-error-temporary-error (0x0505)

   A temporary error such as a buffer full write error, a memory
   overflow (i.e. the document data exceeds the memory of the Printer),
   or a disk full condition, occurs while the IPP Printer processes an
   operation.  The client MAY try the unmodified request again at some
   later point in time with an expectation that the temporary internal
   error condition may have been cleared.  Alternatively, as an
   implementation option, a Printer object MAY delay the response until
   the temporary condition is cleared so that no error is returned.






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13.1.5.7 server-error-not-accepting-jobs (0x0506)

   A temporary error indicating that the Printer is not currently
   accepting jobs, because the administrator has set the value of the
   Printer's "printer-is-accepting-jobs" attribute to 'false' (by means
   outside the scope of this IPP/1.1 document).

13.1.5.8 server-error-busy (0x0507)

   A temporary error indicating that the Printer is too busy processing
   jobs and/or other requests. The client SHOULD try the unmodified
   request again at some later point in time with an expectation that
   the temporary busy condition will have been cleared.

13.1.5.9 server-error-job-canceled (0x0508)

   An error indicating that the job has been canceled by an operator or
   the system while the client was transmitting the data to the IPP
   Printer.  If a job-id and job-uri had been created, then they are
   returned in the Print-Job, Send-Document, or Send-URI response as
   usual; otherwise, no job-id and job-uri are returned in the response.

13.1.5.10 server-error-multiple-document-jobs-not-supported (0x0509)

   The IPP object does not support multiple documents per job and a
   client attempted to supply document data with a second Send-Document
   or Send-URI operation.

13.2 Status Codes for IPP Operations

   PJ = Print-Job, PU = Print-URI, CJ = Create-Job, SD = Send-Document
   SU = Send-URI, V = Validate-Job, GA = Get-Job-Attributes and
   Get-Printer-Attributes, GJ = Get-Jobs, C = Cancel-Job


















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                                                  IPP Operations
   IPP Status Keyword                       PJ PU CJ SD SU V GA GJ C
   ------------------                       -- -- -- -- -- - -- -- -
   successful-ok                            x  x  x  x  x  x x  x  x
   successful-ok-ignored-or-substituted-    x  x  x  x  x  x x  x  x
        attributes
   successful-ok-conflicting-attributes     x  x  x  x  x  x x  x  x
   client-error-bad-request                 x  x  x  x  x  x x  x  x
   client-error-forbidden                   x  x  x  x  x  x x  x  x
   client-error-not-authenticated           x  x  x  x  x  x x  x  x
   client-error-not-authorized              x  x  x  x  x  x x  x  x
   client-error-not-possible                x  x  x  x  x  x x  x  x
   client-error-timeout                              x  x
   client-error-not-found                   x  x  x  x  x  x x  x  x
   client-error-gone                        x  x  x  x  x  x x  x  x
   client-error-request-entity-too-large    x  x  x  x  x  x x  x  x
   client-error-request-value-too-long      x  x  x  x  x  x x  x  x
   client-error-document-format-not-        x  x     x  x  x x
        supported
   client-error-attributes-or-values-not-   x  x  x  x  x  x x  x  x
        supported
   client-error-uri-scheme-not-supported       x        x
   client-error-charset-not-supported       x  x  x  x  x  x x  x  x
   client-error-conflicting-attributes      x  x  x  x  x  x x  x  x
   client-error-compression-not-supported   x  x     x  x  x
   client-error-compression-error           x  x     x  x
   client-error-document-format-error       x  x     x  x
   client-error-document-access-error          x        x
   server-error-internal-error              x  x  x  x  x  x x  x  x
   server-error-operation-not-supported        x  x  x  x
   server-error-service-unavailable         x  x  x  x  x  x x  x  x
   server-error-version-not-supported       x  x  x  x  x  x x  x  x
   server-error-device-error                x  x  x  x  x
   server-error-temporary-error             x  x  x  x  x
   server-error-not-accepting-jobs          x  x  x        x
   server-error-busy                        x  x  x  x  x  x x  x  x
   server-error-job-canceled                x        x  x
   server-error-multiple-document-jobs-              x  x
          not-supported

   HJ = Hold-Job, RJ = Release-Job, RS = Restart-Job
   PP = Pause-Printer, RP = Resume-Printer, PJ = Purge-Jobs









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                                            IPP Operations (cont.)
   IPP Status Keyword                       HJ RJ RS PP RP PJ
   ------------------                       -- -- -- -- -- --
   successful-ok                            x  x  x  x  x  x
   successful-ok-ignored-or-substituted-    x  x  x  x  x  x
        attributes
   successful-ok-conflicting-attributes     x  x  x  x  x  x
   client-error-bad-request                 x  x  x  x  x  x
   client-error-forbidden                   x  x  x  x  x  x
   client-error-not-authenticated           x  x  x  x  x  x
   client-error-not-authorized              x  x  x  x  x  x
   client-error-not-possible                x  x  x  x  x  x
   client-error-timeout
   client-error-not-found                   x  x  x  x  x  x
   client-error-gone                        x  x  x  x  x  x
   client-error-request-entity-too-large    x  x  x  x  x  x
   client-error-request-value-too-long      x  x  x  x  x  x
   client-error-document-format-not-
        supported
   client-error-attributes-or-values-not-   x  x  x  x  x  x
        supported
   client-error-uri-scheme-not-supported
   client-error-charset-not-supported       x  x  x  x  x  x
   client-error-conflicting-attributes      x  x  x  x  x  x
   client-error-compression-not-supported
   client-error-compression-error
   client-error-document-format-error
   client-error-document-access-error
   server-error-internal-error              x  x  x  x  x  x
   server-error-operation-not-supported     x  x  x  x  x  x
   server-error-service-unavailable         x  x  x  x  x  x
   server-error-version-not-supported       x  x  x  x  x  x
   server-error-device-error
   server-error-temporary-error             x  x  x  x  x  x
   server-error-not-accepting-jobs
   server-error-busy                        x  x  x  x  x  x
   server-error-job-canceled
   server-error-multiple-document-jobs-
          not-supported












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14.  APPENDIX C:  "media" keyword values

   Standard keyword values are taken from several sources.

   Standard values are defined (taken from DPA[ISO10175] and the Printer
   MIB[RFC1759]):

    'default': The default medium for the output device
    'iso-a4-white': Specifies the ISO A4 white medium: 210 mm x 297 mm
    'iso-a4-colored': Specifies the ISO A4 colored medium: 210 mm x 297
       mm
    'iso-a4-transparent' Specifies the ISO A4 transparent medium: 210 mm
       x 297 mm
    'iso-a3-white': Specifies the ISO A3 white medium: 297 mm x 420 mm
    'iso-a3-colored': Specifies the ISO A3 colored medium: 297 mm x 420
       mm
    'iso-a5-white': Specifies the ISO A5 white medium: 148 mm x 210 mm
    'iso-a5-colored': Specifies the ISO A5 colored medium: 148 mm x 210
       mm
    'iso-b4-white': Specifies the ISO B4 white medium: 250 mm x 353 mm
    'iso-b4-colored': Specifies the ISO B4 colored medium: 250 mm x 353
       mm
    'iso-b5-white': Specifies the ISO B5 white medium: 176 mm x 250 mm
    'iso-b5-colored': Specifies the ISO B5 colored medium: 176 mm x 250
       mm
    'jis-b4-white': Specifies the JIS B4 white medium: 257 mm x 364 mm
    'jis-b4-colored': Specifies the JIS B4 colored medium: 257 mm x 364
       mm
    'jis-b5-white': Specifies the JIS B5 white medium: 182 mm x 257 mm
    'jis-b5-colored': Specifies the JIS B5 colored medium: 182 mm x 257
       mm

   The following standard values are defined for North American media:

    'na-letter-white': Specifies the North American letter white medium
    'na-letter-colored': Specifies the North American letter colored
       medium
    'na-letter-transparent': Specifies the North American letter
       transparent medium
    'na-legal-white': Specifies the North American legal white medium
    'na-legal-colored': Specifies the North American legal colored
       medium









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   The following standard values are defined for envelopes:

    'iso-b4-envelope': Specifies the ISO B4 envelope medium
    'iso-b5-envelope': Specifies the ISO B5 envelope medium
    'iso-c3-envelope': Specifies the ISO C3 envelope medium
    'iso-c4-envelope': Specifies the ISO C4 envelope medium
    'iso-c5-envelope': Specifies the ISO C5 envelope medium
    'iso-c6-envelope': Specifies the ISO C6 envelope medium
    'iso-designated-long-envelope': Specifies the ISO Designated Long
       envelope medium
    'na-10x13-envelope': Specifies the North American 10x13 envelope
       medium
    'na-9x12-envelope': Specifies the North American 9x12 envelope
       medium
    'monarch-envelope': Specifies the Monarch envelope
    'na-number-10-envelope': Specifies the North American number 10
       business envelope medium
    'na-7x9-envelope': Specifies the North American 7x9 inch envelope
    'na-9x11-envelope': Specifies the North American 9x11 inch
       envelope
    'na-10x14-envelope': Specifies the North American 10x14 inch
       envelope
    'na-number-9-envelope': Specifies the North American number 9
       business envelope
    'na-6x9-envelope': Specifies the North American 6x9 inch envelope
    'na-10x15-envelope': Specifies the North American 10x15 inch
       envelope

   The following standard values are defined for the less commonly used
   media:

 'executive-white': Specifies the white executive medium
 'folio-white': Specifies the folio white medium
 'invoice-white': Specifies the white invoice medium
 'ledger-white': Specifies the white ledger medium
 'quarto-white': Specified the white quarto medium
 'iso-a0-white': Specifies the ISO A0 white medium: 841 mm x 1189 mm
 'iso-a0-transparent': Specifies the ISO A0 transparent medium: 841 mm
    x 1189 mm
 'iso-a0-translucent': Specifies the ISO A0 translucent medium: 841 mm
    x 1189 mm
 'iso-a1-white': Specifies the ISO A1 white medium: 594 mm x 841 mm
 'iso-a1-transparent': Specifies the ISO A1 transparent medium: 594 mm
    x 841 mm
 'iso-a1-translucent': Specifies the ISO A1 translucent medium: 594 mm
    x 841 mm
 'iso-a2-white': Specifies the ISO A2 white medium: 420 mm x 594 mm




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 'iso-a2-transparent': Specifies the ISO A2 transparent medium: 420 mm
    x 594 mm
 'iso-a2-translucent': Specifies the ISO A2 translucent medium: 420 mm
    x 594 mm
 'iso-a3-transparent': Specifies the ISO A3 transparent medium: 297 mm
    x 420 mm
 'iso-a3-translucent': Specifies the ISO A3 translucent medium: 297 mm
    x 420 mm
 'iso-a4-translucent': Specifies the ISO A4 translucent medium: 210 mm
    x 297 mm
 'iso-a5-transparent': Specifies the ISO A5 transparent medium: 148 mm
    x 210 mm
 'iso-a5-translucent': Specifies the ISO A5 translucent medium: 148 mm
    x 210 mm
 'iso-a6-white': Specifies the ISO A6 white medium: 105 mm x 148 mm
 'iso-a7-white': Specifies the ISO A7 white medium: 74 mm x 105 mm
 'iso-a8-white': Specifies the ISO A8 white medium: 52 mm x 74 mm
 'iso-a9-white': Specifies the ISO A9 white medium: 37 mm x 52 mm
 'iso-a10-white': Specifies the ISO A10 white medium: 26 mm x 37 mm
 'iso-b0-white': Specifies the ISO B0 white medium: 1000 mm x 1414 mm
 'iso-b1-white': Specifies the ISO B1 white medium: 707 mm x 1000 mm
 'iso-b2-white': Specifies the ISO B2 white medium: 500 mm x 707 mm
 'iso-b3-white': Specifies the ISO B3 white medium: 353 mm x 500 mm
 'iso-b6-white': Specifies the ISO B6 white medium: 125 mm x 176 mm
 'iso-b7-white': Specifies the ISO B7 white medium: 88 mm x 125 mm
 'iso-b8-white': Specifies the ISO B8 white medium: 62 mm x 88 mm
 'iso-b9-white': Specifies the ISO B9 white medium: 44 mm x 62 mm
 'iso-b10-white': Specifies the ISO B10 white medium: 31 mm x 44 mm
 'jis-b0-white': Specifies the JIS B0 white medium: 1030 mm x 1456 mm
 'jis-b0-transparent': Specifies the JIS B0 transparent medium: 1030
    mm x 1456 mm
 'jis-b0-translucent': Specifies the JIS B0 translucent medium: 1030
    mm x 1456 mm
 'jis-b1-white': Specifies the JIS B1 white medium: 728 mm x 1030 mm
 'jis-b1-transparent': Specifies the JIS B1 transparent medium: 728 mm
    x 1030 mm
 'jis-b1-translucent': Specifies the JIS B1 translucent medium: 728 mm
    x 1030 mm
 'jis-b2-white': Specifies the JIS B2 white medium: 515 mm x 728 mm
 'jis-b2-transparent': Specifies the JIS B2 transparent medium: 515 mm
    x 728 mm
 'jis-b2-translucent': Specifies the JIS B2 translucent medium: 515 mm
    x 728 mm
 'jis-b3-white': Specifies the JIS B3 white medium: 364 mm x 515 mm
 'jis-b3-transparent': Specifies the JIS B3 transparent medium: 364 mm
    x 515 mm
 'jis-b3-translucent': Specifies the JIS B3 translucent medium: 364 mm
    x 515 mm



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 'jis-b4-transparent': Specifies the JIS B4 transparent medium: 257 mm
    x 364 mm
 'jis-b4-translucent': Specifies the JIS B4 translucent medium: 257 mm
    x 364 mm
 'jis-b5-transparent': Specifies the JIS B5 transparent medium: 182 mm
    x 257 mm
 'jis-b5-translucent': Specifies the JIS B5 translucent medium: 182 mm
    x 257 mm
 'jis-b6-white': Specifies the JIS B6 white medium: 128 mm x 182 mm
 'jis-b7-white': Specifies the JIS B7 white medium: 91 mm x 128 mm
 'jis-b8-white': Specifies the JIS B8 white medium: 64 mm x 91 mm
 'jis-b9-white': Specifies the JIS B9 white medium: 45 mm x 64 mm
 'jis-b10-white': Specifies the JIS B10 white medium: 32 mm x 45 mm

   The following standard values are defined for American Standard (i.e.
   ANSI) engineering media:

    'a-white': Specifies the engineering ANSI A size white medium: 8.5
       inches x 11 inches
    'a-transparent': Specifies the engineering ANSI A size transparent
       medium: 8.5 inches x 11 inches
    'a-translucent': Specifies the engineering ANSI A size translucent
       medium: 8.5 inches x 11 inches
    'b-white': Specifies the engineering ANSI B size white medium: 11
       inches x 17 inches
    'b-transparent': Specifies the engineering ANSI B size transparent
       medium: 11 inches x 17 inches)
    'b-translucent': Specifies the engineering ANSI B size translucent
       medium: 11 inches x 17 inches
    'c-white': Specifies the engineering ANSI C size white medium: 17
       inches x 22 inches
    'c-transparent': Specifies the engineering ANSI C size transparent
       medium: 17 inches x 22 inches
    'c-translucent': Specifies the engineering ANSI C size translucent
       medium: 17 inches x 22 inches
    'd-white': Specifies the engineering ANSI D size white medium: 22
       inches x 34 inches
    'd-transparent': Specifies the engineering ANSI D size transparent
       medium: 22 inches x 34 inches
    'd-translucent': Specifies the engineering ANSI D size translucent
       medium: 22 inches x 34 inches
    'e-white': Specifies the engineering ANSI E size white medium: 34
       inches x 44 inches
    'e-transparent': Specifies the engineering ANSI E size transparent
       medium: 34 inches x 44 inches
    'e-translucent': Specifies the engineering ANSI E size translucent
       medium: 34 inches x 44 inches




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   The following standard values are defined for American Standard (i.e.
   ANSI) engineering media for devices that provide the "synchro-cut"
   feature (see section 14.1):

 'axsynchro-white': Specifies the roll paper having the width of the
    longer edge (11 inches) of the engineering ANSI A size white medium
    and cuts synchronizing with data.
 'axsynchro-transparent': Specifies the roll paper having the width of
    the longer edge (11 inches) of the engineering ANSI A size
    transparent medium and cuts synchronizing with data.
 'axsynchro-translucent': Specifies the roll paper having the width of
    the longer edge (11 inches) of the engineering ANSI A size
    translucent medium and cuts synchronizing with data.
 'bxsynchro-white': Specifies the roll paper having the width of the
    longer edge (17 inches) of the engineering ANSI B size white medium
    and cuts synchronizing with data.
 'bxsynchro-transparent': Specifies the roll paper having the width of
    the longer edge (17 inches) of the engineering ANSI B size
    transparent medium and cuts synchronizing with data.
 'bxsynchro-translucent': Specifies the roll paper having the width of
    the longer edge (17 inches) of the engineering ANSI B size
    translucent medium and cuts synchronizing with data.
 'cxsynchro-white': Specifies the roll paper having the width of the
    longer edge (22 inches) of the engineering ANSI C size white medium
    and cuts synchronizing with data.
 'cxsynchro-transparent': Specifies the roll paper having the width of
    the longer edge (22 inches) of the engineering ANSI C size
    transparent medium and cuts synchronizing with data.
 'cxsynchro-translucent': Specifies the roll paper having the width of
    the longer edge (22 inches) of the engineering ANSI C size
    translucent medium and cuts synchronizing with data.
 'dxsynchro-white': Specifies the roll paper having the width of the
    longer edge (34 inches) of the engineering ANSI D size white medium
    and cuts synchronizing with data.
 'dxsynchro-transparent': Specifies the roll paper having the width of
    the longer edge (34 inches) of the engineering ANSI D size
    transparent medium and cuts synchronizing with data.
 'dxsynchro-translucent': Specifies the roll paper having the width of
    the longer edge (34 inches) of the engineering ANSI D size
    translucent medium and cuts synchronizing with data.
 'exsynchro-white': Specifies the roll paper having the width of the
    longer edge (44 inches) of the engineering ANSI E size white medium
    and cuts synchronizing with data.
 'exsynchro-transparent': Specifies the roll paper having the width of
    the longer edge (44 inches) of the engineering ANSI E size
    transparent medium and cuts synchronizing with data.





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 'exsynchro-translucent': Specifies the roll paper having the width of
    the longer edge (44 inches) of the engineering ANSI E size
    translucent medium and cuts synchronizing with data.

   The following standard values are defined for American Architectural
   engineering media:

 'arch-a-white': Specifies the Architectural A size white medium: 9
    inches x 12 inches
 'arch-a-transparent': Specifies the Architectural A size transparent
    medium: 9 inches x 12 inches
 'arch-a-translucent': Specifies the Architectural A size translucent
    medium: 9 inches x 12 inches
 'arch-b-white': Specifies the Architectural B size white medium: 12
    inches x 18 inches
 'arch-b-transparent': Specifies the Architectural B size transparent
    medium: 12 inches x 18 inches
 'arch-b-translucent': Specifies the Architectural B size translucent
    medium: 12 inches x 18 inches
 'arch-c-white': Specifies the Architectural C size white medium: 18
    inches x 24 inches
 'arch-c-transparent': Specifies the Architectural C size transparent
    medium: 18 inches x 24 inches
 'arch-c-translucent': Specifies the Architectural C size translucent
    medium: 18 inches x 24 inches
 'arch-d-white': Specifies the Architectural D size white medium: 24
    inches x 36 inches
 'arch-d-transparent': Specifies the Architectural D size transparent
    medium: 24 inches x 36 inches
 'arch-d-translucent': Specifies the Architectural D size translucent
    medium: 24 inches x 36 inches
 'arch-e-white': Specifies the Architectural E size white medium: 36
    inches x 48 inches
 'arch-e-transparent': Specifies the Architectural E size transparent
    medium: 36 inches x 48 inches
 'arch-e-translucent': Specifies the Architectural E size translucent
    medium: 36 inches x 48 inches

   The following standard values are defined for American Architectural
   engineering media for devices that provide the "synchro-cut" feature
   (see section 14.1):

 'arch-axsynchro-white': Specifies the roll paper having the width of
    the longer edge (12 inches) of the Architectural A size white
    medium and cuts synchronizing with data.
 'arch-axsynchro-transparent': Specifies the roll paper having the
    width of the longer edge (12 inches) of the Architectural A size
    transparent medium and cuts synchronizing with data.



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 'arch-axsynchro-translucent': Specifies the roll paper having the
    width of the longer edge (12 inches) of the Architectural A size
    translucent medium and cuts synchronizing with data.
 'arch-bxsynchro-white': Specifies the roll paper having the width of
    the longer edge (18 inches) of the Architectural B size white
    medium and cuts synchronizing with data.
 'arch-bxsynchro-transparent': Specifies the roll paper having the
    width of the longer edge (18 inches) of the Architectural B size
    transparent medium and cuts synchronizing with data.
 'arch-bxsynchro-translucent': Specifies the roll paper having the
    width of the longer edge (18 inches) of the Architectural B size
    translucent medium and cuts synchronizing with data.
 'arch-cxsynchro-white': Specifies the roll paper having the width of
    the longer edge (24 inches) of the Architectural C size white
    medium and cuts synchronizing with data.
 'arch-cxsynchro-transparent': Specifies the roll paper having the
    width of the longer edge (24 inches) of the Architectural C size
    transparent medium and cuts synchronizing with data.
 'arch-cxsynchro-translucent': Specifies the roll paper having the
    width of the longer edge (24 inches) of the Architectural C size
    translucent medium and cuts synchronizing with data.
 'arch-dxsynchro-white': Specifies the roll paper having the width of
    the longer edge (36 inches) of the Architectural D size white
    medium and cuts synchronizing with data.
 'arch-dxsynchro-transparent': Specifies the roll paper having the
    width of the longer edge (36 inches) of the Architectural D size
    transparent medium and cuts synchronizing with data.
 'arch-dxsynchro-translucent': Specifies the roll paper having the
    width of the longer edge (36 inches) of the Architectural D size
    translucent medium and cuts synchronizing with data.
 'arch-exsynchro-white': Specifies the roll paper having the width of
    the longer edge (48 inches) of the Architectural E size white
    medium and cuts synchronizing with data.
 'arch-exsynchro-transparent': Specifies the roll paper having the
    width of the longer edge (48 inches) of the Architectural E size
    transparent medium and cuts synchronizing with data.
 'arch-exsynchro-translucent': Specifies the roll paper having the
    width of the longer edge (48 inches) of the Architectural E size
    translucent medium and cuts synchronizing with data.

   The following standard values are defined for Japanese and European
   Standard (i.e. ISO) engineering media, which are of a long fixed size
   [ASME-Y14.1M]:

 'iso-a1x3-white': Specifies the ISO A1X3 white medium having the
      width of the longer edge (841 mm) of the ISO A1 medium





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 'iso-a1x3-transparent': Specifies the ISO A1X3 transparent medium
      having the width of the longer edge (841 mm) of the ISO A1
      medium
 'iso-a1x3-translucent': Specifies the ISO A1X3 translucent medium
      having the width of the longer edge (841 mm) of the ISO A1
      medium
 'iso-a1x4-white': Specifies the ISO A1X4 white medium having the
      width of the longer edge (841 mm) of the ISO A1 medium
 'iso-a1x4-transparent': Specifies the ISO A1X4 transparent medium
      having the width of the longer edge (841 mm) of the ISO A1
      medium
 'iso-a1x4- translucent': Specifies the ISO A1X4 translucent medium
      having the width of the longer edge (841 mm) of the ISO A1
      medium
 'iso-a2x3-white': Specifies the ISO A2X3 white medium having the
      width of the longer edge (594 mm) of the ISO A2 medium
 'iso-a2x3-transparent': Specifies the ISO A2X3 transparent medium
      having the width of the longer edge (594 mm) of the ISO A2
      medium
 'iso-a2x3-translucent': Specifies the ISO A2X3 translucent medium
      having the width of the longer edge (594 mm) of the ISO A2
      medium
 'iso-a2x4-white': Specifies the ISO A2X4 white medium having the
      width of the longer edge (594 mm) of the ISO A2 medium
 'iso-a2x4-transparent': Specifies the ISO A2X4 transparent medium
      having the width of the longer edge (594 mm) of the ISO A2
      medium
 'iso-a2x4-translucent': Specifies the ISO A2X4 translucent medium
      having the width of the longer edge (594 mm) of the ISO A2
      medium
 'iso-a2x5-white': Specifies the ISO A2X5 white medium having the
      width of the longer edge (594 mm) of the ISO A2 medium
 'iso-a2x5-transparent': Specifies the ISO A2X5 transparent medium
      having the width of the longer edge (594 mm) of the ISO A2
      medium
 'iso-a2x5-translucent': Specifies the ISO A2X5 translucent medium
      having the width of the longer edge (594 mm) of the ISO A2
      medium
 'iso-a3x3-white': Specifies the ISO A3X3 white medium having the
      width of the longer edge (420 mm) of the ISO A3 medium
 'iso-a3x3-transparent': Specifies the ISO A3X3 transparent medium
      having the width of the longer edge (420 mm) of the ISO A3
      medium
 'iso-a3x3-translucent': Specifies the ISO A3X3 translucent medium
      having the width of the longer edge (420 mm) of the ISO A3
      medium
 'iso-a3x4-white': Specifies the ISO A3X4 white medium having the
      width of the longer edge (420 mm) of the ISO A3 medium



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 'iso-a3x4-transparent': Specifies the ISO A3X4 transparent medium
      having the width of the longer edge (420 mm) of the ISO A3
      medium
 'iso-a3x4-translucent': Specifies the ISO A3X4 translucent medium
      having the width of the longer edge (420 mm) of the ISO A3
      medium
 'iso-a3x5-white': Specifies the ISO A3X5 white medium having the
      width of the longer edge (420 mm) of the ISO A3 medium
 'iso-a3x5-transparent': Specifies the ISO A3X5 transparent medium
      having the width of the longer edge (420 mm) of the ISO A3
      medium
 'iso-a3x5-translucent': Specifies the ISO A3X5 translucent medium
      having the width of the longer edge (420 mm) of the ISO A3
      medium
 'iso-a3x6-white': Specifies the ISO A3X6 white medium having the
      width of the longer edge (420 mm) of the ISO A3 medium
 'iso-a3x6-transparent': Specifies the ISO A3X6 transparent medium
      having the width of the longer edge (420 mm) of the ISO A3
      medium
 'iso-a3x6-translucent': Specifies the ISO A3X6 translucent medium
      having the width of the longer edge (420 mm) of the ISO A3
      medium
 'iso-a3x7-white': Specifies the ISO A3X7 white medium having the
      width of the longer edge (420 mm) of the ISO A3 medium
 'iso-a3x7-transparent': Specifies the ISO A3X7 transparent medium
      having the width of the longer edge (420 mm) of the ISO A3
      medium
 'iso-a3x7-translucent'': Specifies the ISO A3X7 translucent' medium
      having the width of the longer edge (420 mm) of the ISO A3
      medium
 'iso-a4x3-white': Specifies the ISO A4X3 white medium having the
      width of the longer edge (297 mm) of the ISO A4 medium
 'iso-a4x3-transparent': Specifies the ISO A4X3 transparent medium
      having the width of the longer edge (297 mm) of the ISO A4
      medium
 'iso-a4x3-translucent'': Specifies the ISO A4X3 translucent' medium
      having the width of the longer edge (297 mm) of the ISO A4
      medium
 'iso-a4x4-white': Specifies the ISO A4X4 white medium having the
      width of the longer edge (297 mm) of the ISO A4 medium
 'iso-a4x4-transparent': Specifies the ISO A4X4 transparent medium
      having the width of the longer edge (297 mm) of the ISO A4
      medium
 'iso-a4x4-translucent': Specifies the ISO A4X4 translucent medium
      having the width of the longer edge (297 mm) of the ISO A4
      medium
 'iso-a4x5-white': Specifies the ISO A4X5 white medium having the
      width of the longer edge (297 mm) of the ISO A4 medium



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 'iso-a4x5-transparent': Specifies the ISO A4X5 transparent medium
      having the width of the longer edge (297 mm) of the ISO A4
      medium
 'iso-a4x5-translucent': Specifies the ISO A4X5 translucent medium
      having the width of the longer edge (297 mm) of the ISO A4
      medium
 'iso-a4x6-white': Specifies the ISO A4X6 white medium having the
      width of the longer edge (297 mm) of the ISO A4 medium
 'iso-a4x6-transparent': Specifies the ISO A4X6 transparent medium
      having the width of the longer edge (297 mm) of the ISO A4
      medium
 'iso-a4x6-translucent': Specifies the ISO A4X6 translucent medium
      having the width of the longer edge (297 mm) of the ISO A4
      medium
 'iso-a4x7-white': Specifies the ISO A4X7 white medium having the
      width of the longer edge (297 mm) of the ISO A4 medium
 'iso-a4x7-transparent': Specifies the ISO A4X7 transparent medium
      having the width of the longer edge (297 mm) of the ISO A4
      medium
 'iso-a4x7-translucent': Specifies the ISO A4X7 translucent medium
      having the width of the longer edge (297 mm) of the ISO A4
      medium
 'iso-a4x8-white': Specifies the ISO A4X8 white medium having the
      width of the longer edge (297 mm) of the ISO A4 medium
 'iso-a4x8-transparent': Specifies the ISO A4X8 transparent medium
      having the width of the longer edge (297 mm) of the ISO A4
      medium
 'iso-a4x8-translucent': Specifies the ISO A4X8 translucent medium
      having the width of the longer edge (297 mm) of the ISO A4
      medium
 'iso-a4x9-white': Specifies the ISO A4X9 white medium having the
      width of the longer edge (297 mm) of the ISO A4 medium
 'iso-a4x9-transparent': Specifies the ISO A4X9 transparent medium
      having the width of the longer edge (297 mm) of the ISO A4
      medium
 'iso-a4x9-translucent': Specifies the ISO A4X9 translucent medium
      having the width of the longer edge (297 mm) of the ISO A4
      medium

   The following standard values are defined for Japanese and European
   Standard (i.e. ISO) engineering media, which are either a long fixed
   size [ASME-Y14.1M] or roll feed, for devices that provide the
   "synchro-cut" feature (see section 14.1):

 'iso-a0xsynchro-white': Specifies the paper having the width of the
      longer edge (1189 mm) of the ISO A0 white medium and cuts
      synchronizing with data.




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 'iso-a0xsynchro-transparent': Specifies the paper having the width of
      the longer edge (1189 mm) of the ISO A0 transparent medium and
      cuts synchronizing with data.
 'iso-a0xsynchro-translucent': Specifies the paper having the width of
      the longer edge (1189 mm) of the ISO A0 translucent medium and
      cuts synchronizing with data.
 'iso-a1xsynchro-white': Specifies the paper having the width of the
      longer edge (841 mm) of the ISO A1 white medium and cuts
      synchronizing with data.
 'iso-a1xsynchro-transparent': Specifies the paper having the width of
      the longer edge (841 mm) of the ISO A1 transparent medium and
      cuts synchronizing with data.
 'iso-a1xsynchro-translucent': Specifies the paper having the width of
      the longer edge (841 mm) of the ISO A1 translucent medium and
      cuts synchronizing with data.
 'iso-a2xsynchro-white': Specifies the paper having the width of the
      longer edge (594 mm) of the ISO A2 white medium and cuts
      synchronizing with data.
 'iso-a2xsynchro-transparent': Specifies the paper having the width of
      the longer edge (594 mm) of the ISO A2 transparent medium and
      cuts synchronizing with data.
 'iso-a2xsynchro-translucent': Specifies the paper having the width of
      the longer edge (594 mm) of the ISO A2 translucent medium and
      cuts synchronizing with data.
 'iso-a3xsynchro-white': Specifies the paper having the width of the
      longer edge (420 mm) of the ISO A3 white medium and cuts
      synchronizing with data.
 'iso-a3xsynchro-transparent': Specifies the paper having the width of
      the longer edge (420 mm) of the ISO A3 transparent medium and
      cuts synchronizing with data.
 'iso-a3xsynchro-translucent': Specifies the paper having the width of
      the longer edge (420 mm) of the ISO A3 translucent medium and
      cuts synchronizing with data.
 'iso-a4xsynchro-white': Specifies the paper having the width of the
      longer edge (297 mm) of the ISO A4 white medium and cuts
      synchronizing with data.
 'iso-a4xsynchro-transparent': Specifies the paper having the width of
      the longer edge (297 mm) of the ISO A4 transparent medium and
      cuts synchronizing with data.
 'iso-a4xsynchro-translucent': Specifies the paper having the width of
      the longer edge (297 mm) of the ISO A4 transparent medium and
      cuts synchronizing with data.

   The following standard values are defined for American Standard (i.e.
   ANSI) engineering media, American Architectural engineering media,
   and Japanese and European Standard (i.e. ISO) engineering media,





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   which are either a long fixed size [ASME-Y14.1M] or roll feed, for
   devices that provide the "synchro-cut" feature and/or the "auto-
   select" feature (see section 14.1):

 'auto-white': Specifies that the printer selects the white medium
      with the appropriate fixed size (e.g. a1, a2, etc.) or data-
      synchro size, and the selection is implementation-defined.
 'auto-transparent': Specifies that the printer selects the
      transparent medium with the appropriate fixed size (e.g. a1, a2,
      etc.) or data-synchro size, and the selection is implementation-
      defined.
 'auto-translucent': Specifies that the printer selects the
      translucent medium with the appropriate fixed size (e.g. a1, a2,
      etc.) or data-synchro size, and the selection is implementation-
      defined.
 'auto-fixed-size-white': Specifies that the printer selects the white
      medium with the appropriate fixed size (e.g. a1, a2, etc.) or
      the appropriate long fixed size listed above.
 'auto-fixed-size-transparent': Specifies that the printer selects the
      transparent medium with the appropriate fixed size (e.g. a1, a2,
      etc.) or the appropriate long fixed size listed above.
 'auto-fixed-size-translucent': Specifies that the printer selects the
      translucent medium with the appropriate fixed size (e.g. a1, a2,
      etc.) or the appropriate long fixed size listed above.
 'auto-synchro-white': Specifies that the printer selects the white
      paper with the appropriate width and cuts it synchronizing with
      data.
 'auto-synchro-transparent': Specifies that the printer selects the
      transparent paper with the appropriate width and cuts it
      synchronizing with data.
 'auto-synchro-translucent': Specifies that the printer selects the
      translucent paper with the appropriate width and cuts it
      synchronizing with data.

   The following standard values are defined for input-trays (from ISO
   DPA and the Printer MIB):

    'top': The top input tray in the printer.
    'middle': The middle input tray in the printer.
    'bottom': The bottom input tray in the printer.
    'envelope': The envelope input tray in the printer.
    'manual': The manual feed input tray in the printer.
    'large-capacity': The large capacity input tray in the printer.
    'main': The main input tray
    'side': The side input tray






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   The following standard values are defined for media sizes (from ISO
   DPA):

 'iso-a0': Specifies the ISO A0 size: 841 mm by 1189 mm as defined in
    ISO 216
 'iso-a1': Specifies the ISO A1 size: 594 mm by 841 mm as defined in
    ISO 216
 'iso-a2': Specifies the ISO A2 size: 420 mm by 594 mm as defined in
    ISO 216
 'iso-a3': Specifies the ISO A3 size: 297 mm by 420 mm as defined in
    ISO 216
 'iso-a4': Specifies the ISO A4 size: 210 mm by 297 mm as defined in
    ISO 216
 'iso-a5': Specifies the ISO A5 size: 148 mm by 210 mm as defined in
    ISO 216
 'iso-a6': Specifies the ISO A6 size: 105 mm by 148 mm as defined in
    ISO 216
 'iso-a7': Specifies the ISO A7 size: 74 mm by 105 mm as defined in
    ISO 216
 'iso-a8': Specifies the ISO A8 size: 52 mm by 74 mm as defined in ISO
    216
 'iso-a9': Specifies the ISO A9 size: 37 mm by 52 mm as defined in ISO
    216
 'iso-a10': Specifies the ISO A10 size: 26 mm by 37 mm as defined in
    ISO 216
 'iso-b0': Specifies the ISO B0 size: 1000 mm by 1414 mm as defined in
    ISO 216
 'iso-b1': Specifies the ISO B1 size: 707 mm by 1000 mm as defined in
    ISO 216
 'iso-b2': Specifies the ISO B2 size: 500 mm by 707 mm as defined in
    ISO 216
 'iso-b3': Specifies the ISO B3 size: 353 mm by 500 mm as defined in
    ISO 216
 'iso-b4': Specifies the ISO B4 size: 250 mm by 353 mm as defined in
    ISO 216
 'iso-b5': Specifies the ISO B5 size: 176 mm by 250 mm as defined in
    ISO 216
 'iso-b6': Specifies the ISO B6 size: 125 mm by 176 mm as defined in
    ISO 216
 'iso-b7': Specifies the ISO B7 size: 88 mm by 125 mm as defined in
    ISO 216
 'iso-b8': Specifies the ISO B8 size: 62 mm by 88 mm as defined in ISO
    216
 'iso-b9': Specifies the ISO B9 size: 44 mm by 62 mm as defined in ISO
    216
 'iso-b10': Specifies the ISO B10 size: 31 mm by 44 mm as defined in
    ISO 216




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 'na-letter': Specifies the North American letter size: 8.5 inches by
    11 inches
 'na-legal': Specifies the North American legal size: 8.5 inches by 14
    inches
 'na-8x10': Specifies the North American 8 inches by 10 inches
 'na-5x7': Specifies the North American 5 inches by 7 inches
 'executive': Specifies the executive size (7.25 X 10.5 in)
 'folio': Specifies the folio size (8.5 X 13 in)
 'invoice': Specifies the invoice size (5.5 X 8.5 in)
 'ledger': Specifies the ledger size (11 X 17 in)
 'quarto': Specifies the quarto size (8.5 X 10.83 in)
 'iso-c3': Specifies the ISO C3 size: 324 mm by 458 mm as defined in
    ISO 269
 'iso-c4': Specifies the ISO C4 size: 229 mm by 324 mm as defined in
    ISO 269
 'iso-c5': Specifies the ISO C5 size: 162 mm by 229 mm as defined in
    ISO 269
 'iso-c6': Specifies the ISO C6 size: 114 mm by 162 mm as defined in
    ISO 269
 'iso-designated-long': Specifies the ISO Designated Long size: 110 mm
    by 220 mm as defined in ISO 269
 'na-10x13-envelope': Specifies the North American 10x13 size: 10
    inches by 13 inches
 'na-9x12-envelope': Specifies the North American 9x12 size: 9 inches
    by 12 inches
 'na-number-10-envelope': Specifies the North American number 10
    business envelope size: 4.125 inches by 9.5 inches
 'na-7x9-envelope': Specifies the North American 7x9 inch envelope
    size
 'na-9x11-envelope': Specifies the North American 9x11 inch envelope
    size
 'na-10x14-envelope': Specifies the North American 10x14 inch envelope
    size
 'na-number-9-envelope': Specifies the North American number 9
    business envelope size
 'na-6x9-envelope': Specifies the North American 6x9 envelope size
 'na-10x15-envelope': Specifies the North American 10x15 envelope size
 'monarch-envelope': Specifies the Monarch envelope size (3.87 x 7.5
    in)
 'jis-b0': Specifies the JIS B0 size: 1030mm x 1456mm
 'jis-b1': Specifies the JIS B1 size: 728mm x 1030mm
 'jis-b2': Specifies the JIS B2 size: 515mm x 728mm
 'jis-b3': Specifies the JIS B3 size: 364mm x 515mm
 'jis-b4': Specifies the JIS B4 size: 257mm x 364mm
 'jis-b5': Specifies the JIS B5 size: 182mm x 257mm
 'jis-b6': Specifies the JIS B6 size: 128mm x 182mm
 'jis-b7': Specifies the JIS B7 size: 91mm x 128mm
 'jis-b8': Specifies the JIS B8 size: 64mm x 91mm



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 'jis-b9': Specifies the JIS B9 size: 45mm x 64mm
 'jis-b10': Specifies the JIS B10 size: 32mm x 45mm

   The following standard values are defined for American Standard (i.e.
   ANSI) engineering media sizes:

    'a': Specifies the engineering ANSI A size medium: 8.5 inches x 11
       inches
    'b': Specifies the engineering ANSI B size medium: 11 inches x 17
       inches
    'c': Specifies the engineering ANSI C size medium: 17 inches x 22
       inches
    'd': Specifies the engineering ANSI D size medium: 22 inches x 34
       inches
    'e': Specifies the engineering ANSI E size medium: 34 inches x 44
       inches

   The following standard values are defined for American Architectural
   engineering media sizes:

    'arch-a': Specifies the Architectural A size medium: 9 inches x 12
       inches
    'arch-b': Specifies the Architectural B size medium: 12 inches x 18
       inches
    'arch-c': Specifies the Architectural C size medium: 18 inches x 24
       inches
    'arch-d': Specifies the Architectural D size medium: 24 inches x 36
       inches
    'arch-e': Specifies the Architectural E size medium: 36 inches x 48
       inches





















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14.1. Examples

   Below are examples to supplement the engineering media value
   definitions.

   Example 1:  "Synchro-Cut", a device cutting the roll paper in
   synchronization with the data

     data height:          A1 height
     data width (shaded):  A1 width < data width < (A1 width) x 2
     specified value:      'iso-a1xsynchro-white'

               |                    |
               |<--- data width --->|
               |                    |
               |              |     |        |
               |<- A1 width ->|<- A1 width ->|
               |              |     |        |
     cross  ^  |              |     |        |
      feed  |  +--------------------------------------------/
 direction  |  |//////////////|/////|        |     ^       /
            |  |//////////////|/////|        |     |      /
            |  |//////////////|/////|        |     |     /
            |  |//////////////|/////|        |     |     \
<-----------+- |//////////////|/////|        |    A1      \  roll
feed        |  |//////////////|/////|        |   height    \  paper
direction      |//////////////|/////|        |     |        \
               |//////////////|/////|        |     |        /
               |//////////////|/////|        |     v       /
               +------------------------------------------/
                                    |
                                    |
                                    |<------ CUT HERE (to synchronize
                                    |                with data width)
                                    |
















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   Example 2: "Auto-Cut", a device cutting the roll paper at multiples
   of fixed-size media width

     data height:          A1 height
     data width (shaded):  A1 width < data width < (A1 width) x 2
     specified value:      'auto-fixed-size-white'

                 |                    |
                 |<--- data width --->|
                 |                    |
                 |              |     |        |
                 |<- A1 width ->|<- A1 width ->|
                 |              |     |        |
     cross  ^    |              |     |        |
      feed  |    +--------------------------------------------/
 direction  |    |//////////////|/////|        |     ^       /
            |    |//////////////|/////|        |     |      /
            |    |//////////////|/////|        |     |     /
            |    |//////////////|/////|        |     |     \
<-----------+-   |//////////////|/////|        |    A1      \  roll
feed        |    |//////////////|/////|        |   height    \  paper
direction        |//////////////|/////|        |     |        \
                 |//////////////|/////|        |     |        /
                 |//////////////|/////|        |     v       /
                 +------------------------------------------/
                                               |
                                               |
                                               |<--- CUT HERE
                                               |      (to synchronize
                                               |       with data width)





















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   Example 3:  the 'iso-a4x4-white' fixed size paper

     paper height:         A4 height
     paper width:          (A4 width) x 4
     specified value:      'iso-a4x4-white'

   |              |              |              |              |
   |<- A4 width ->|<- A4 width ->|<- A4 width ->|<- A4 width ->|
   |              |              |              |              |
   |              |              |              |              |
   +-----------------------------------------------------------+
   |       ^      |              |              |              |
   |       |      |              |              |              |
   |       |      |              |              |              |
   |      A4      |              |              |              |
   |    height    |              |              |              |
   |       |      |              |              |              |
   |       |      |              |              |              |
   |       |      |              |              |              |
   |       v      |              |              |              |
   +-----------------------------------------------------------+






























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   Example 4: "Synchro-Cut", a device cutting the fixed size paper in
   synchronization with the data

     data height:          A4 height
     data width (shaded):  (A4 width) x 2 < data width < (A4 width) x 3
     specified value:      'iso-a4xsynchro-white'

                    |                                   |
                    |<---------- data width ----------->|
                    |                                   |
                    |              |              |     |        |
                    |<- A4 width ->|<- A4 width ->|<- A4 width ->|
                    |              |              |     |        |
        cross  ^    |              |              |     |        |
         feed  |    +--------------------------------------------+
    direction  |    |//////////////|//////////////|/////|    ^   |
               |    |//////////////|//////////////|/////|    |   |
               |    |//////////////|//////////////|/////|    |   |
               |    |//////////////|//////////////|/////|    |   |
   <-----------+-   |//////////////|//////////////|/////|   A4   |
   feed        |    |//////////////|//////////////|/////| height |
   direction        |//////////////|//////////////|/////|    |   |
                    |//////////////|//////////////|/////|    |   |
                    |//////////////|//////////////|/////|    v   |
                    +--------------------------------------------+
                                                        |
                                          CUT HERE ---->|
                                    (to synchronize     |
                                    with data width)    |

15. APPENDIX D: Processing IPP Attributes

   When submitting a print job to a Printer object, the IPP model allows
   a client to supply operation and Job Template attributes along with
   the document data.  These Job Template attributes in the create
   request affect the rendering, production and finishing of the
   documents in the job.  Similar types of instructions may also be
   contained in the document to be printed, that is, embedded within the
   print data itself.  In addition, the Printer has a set of attributes
   that describe what rendering and finishing options which are
   supported by that Printer.  This model, which allows for flexibility
   and power, also introduces the potential that at job submission time,
   these client-supplied attributes may conflict with either:

      - what the implementation is capable of realizing (i.e., what the
        Printer supports), as well as
      - the instructions embedded within the print data itself.




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   The following sections describe how these two types of conflicts are
   handled in the IPP model.

15.1 Fidelity

   If there is a conflict between what the client requests and what a
   Printer object supports, the client may request one of two possible
   conflict handling mechanisms:

      1) either reject the job since the job can not be processed
         exactly as specified, or
      2) allow the Printer to make any changes necessary to proceed with
         processing the Job the best it can.

   In the first case the client is indicating to the Printer object:
   "Print the job exactly as specified with no exceptions, and if that
   can't be done, don't even bother printing the job at all." In the
   second case, the client is indicating to the Printer object: "It is
   more important to make sure the job is printed rather than be
   processed exactly as specified; just make sure the job is printed
   even if some client-supplied attributes need to be changed or
   ignored."

   The IPP model accounts for this situation by introducing an "ipp-
   attribute-fidelity" attribute.

   In a create request, "ipp-attribute-fidelity" is a boolean operation
   attribute that is OPTIONALLY supplied by the client.  The value
   'true' indicates that total fidelity to client supplied Job Template
   attributes and values is required.  The client is requesting that the
   Job be printed exactly as specified, and if that is not possible then
   the job MUST be rejected rather than processed incorrectly.  The
   value 'false' indicates that a reasonable attempt to print the Job is
   acceptable.  If a Printer does not support some of the client
   supplied Job Template attributes or values, the Printer MUST ignore
   them or substitute any supported value for unsupported values,
   respectively.  The Printer may choose to substitute the default value
   associated with that attribute, or use some other supported value
   that is similar to the unsupported requested value.  For example, if
   a client supplies a "media" value of 'na-letter', the Printer may
   choose to substitute 'iso-a4' rather than a default value of
   'envelope'. If the client does not supply the "ipp-attribute-
   fidelity" attribute, the Printer assumes a value of 'false'.

   Each Printer implementation MUST support both types of "fidelity"
   printing (that is whether the client supplies a value of 'true' or
   'false'):




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      - If the client supplies 'false' or does not supply the attribute,
        the Printer object MUST always accept the request by ignoring
        unsupported Job Template attributes and by substituting
        unsupported values of supported Job Template attributes with
        supported values.
      - If the client supplies 'true', the Printer object MUST reject
        the request if the client supplies unsupported Job Template
        attributes.

   Since a client can always query a Printer to find out exactly what is
   and is not supported, "ipp-attribute-fidelity" set to 'false' is
   useful when:

      1) The End-User uses a command line interface to request
         attributes that might not be supported.
      2) In a GUI context, if the End User expects the job might be
         moved to another printer and prefers a sub-optimal result to
         nothing at all.
      3) The End User just wants something reasonable in lieu of nothing
         at all.

15.2 Page Description Language (PDL) Override

   If there is a conflict between the value of an IPP Job Template
   attribute and a corresponding instruction in the document data, the
   value of the IPP attribute SHOULD take precedence over the document
   instruction.  Consider the case where a previously formatted file of
   document data is sent to an IPP Printer.  In this case, if the client
   supplies any attributes at job submission time, the client desires
   that those attributes override the embedded instructions.  Consider
   the case were a previously formatted document has embedded in it
   commands to load 'iso-a4' media.  However, the document is passed to
   an end user that only has access to a printer with 'na-letter' media
   loaded.  That end user most likely wants to submit that document to
   an IPP Printer with the "media" Job Template attribute set to 'na-
   letter'.  The job submission attribute should take precedence over
   the embedded PDL instruction.  However, until companies that supply
   document data interpreters allow a way for external IPP attributes to
   take precedence over embedded job production instructions, a Printer
   might not be able to support the semantics that IPP attributes
   override the embedded instructions.

   The IPP model accounts for this situation by introducing a "pdl-
   override-supported" attribute that describes the Printer objects
   capabilities to override instructions embedded in the PDL data
   stream.  The value of the "pdl-override-supported" attribute is
   configured by means outside the scope of this IPP/1.1 document.




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   This REQUIRED Printer attribute takes on the following values:

      - 'attempted': This value indicates that the Printer object
        attempts to make the IPP attribute values take precedence over
        embedded instructions in the document data, however there is no
        guarantee.
      - 'not-attempted': This value indicates that the Printer object
        makes no attempt to make the IPP attribute values take
        precedence over embedded instructions in the document data.

   At job processing time, an implementation that supports the value of
   'attempted' might do one of several different actions:

      1) Generate an output device specific command sequence to realize
         the feature represented by the IPP attribute value.
      2) Parse the document data itself and replace the conflicting
         embedded instruction with a new embedded instruction that
         matches the intent of the IPP attribute value.
      3) Indicate to the Printer that external supplied attributes take
         precedence over embedded instructions and then pass the
         external IPP attribute values to the document data interpreter.
      4) Anything else that allows for the semantics that IPP attributes
         override embedded document data instructions.

   Since 'attempted' does not offer any type of guarantee, even though a
   given Printer object might not do a very "good" job of attempting to
   ensure that IPP attributes take a higher precedence over instructions
   embedded in the document data, it would still be a conforming
   implementation.

   At job processing time, an implementation that supports the value of
   'not-attempted' might do one of the following actions:

      1) Simply pre-pend the document data with the PDL instruction that
         corresponds to the client-supplied PDL attribute, such that if
         the document data also has the same PDL instruction, it will
         override what the Printer object pre-pended.  In other words,
         this implementation is using the same implementation semantics
         for the client-supplied IPP attributes as for the Printer
         object defaults.

      2) Parse the document data and replace the conflicting embedded
         instruction with a new embedded instruction that approximates,
         but does not match, the semantic intent of the IPP attribute
         value.

   Note:  The "ipp-attribute-fidelity" attribute applies to the
   Printer's ability to either accept or reject other unsupported Job



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   Template attributes.  In other words, if "ipp-attribute-fidelity" is
   set to 'true', a Job is accepted if and only if the client supplied
   Job Template attributes and values are supported by the Printer.
   Whether these attributes actually affect the processing of the Job
   when the document data contains embedded instructions depends on the
   ability of the Printer to override the instructions embedded in the
   document data with the semantics of the IPP attributes.  If the
   document data attributes can be overridden ("pdl-override-supported"
   set to 'attempted'), the Printer makes an attempt to use the IPP
   attributes when processing the Job. If the document data attributes
   can not be overridden ("pdl-override-supported" set to 'not-
   attempted'), the Printer makes no attempt to override the embedded
   document data instructions with the IPP attributes when processing
   the Job, and hence, the IPP attributes may fail to affect the Job
   processing and output when the corresponding instruction is embedded
   in the document data.

15.3 Using Job Template Attributes During Document Processing.

   The Printer object uses some of the Job object's Job Template
   attributes during the processing of the document data associated with
   that job.  These include, but are not limited to, "orientation-
   requested", "number-up", "sides", "media", and "copies".  The
   processing of each document in a Job Object MUST follow the steps
   below. These steps are intended only to identify when and how
   attributes are to be used in processing document data and any
   alternative steps that accomplishes the same effect can be used to
   implement this specification document.

      1. Using the client supplied "document-format" attribute or some
         form of document format detection algorithm (if the value of
         "document-format" is not specific enough), determine whether or
         not the document data has already been formatted for printing.
         If the document data has been formatted, then go to step 2.
         Otherwise, the document data MUST be formatted. The formatting
         detection algorithm is implementation defined and is not
         specified by this document.  The formatting of the document
         data uses the "orientation-requested" attribute to determine
         how the formatted print data should be placed on a print-stream
         page, see section 4.2.10 for the details.

      2. The document data is in the form of a print-stream in a known
         media type. The "page-ranges" attribute is used to select, as
         specified in section 4.2.7, a sub-sequence of the pages in the
         print-stream that are to be processed and images.

      3. The input to this step is a sequence of print-stream pages.
         This step is controlled by the "number-up" attribute. If the



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         value of "number-up" is N, then during the processing of the
         print-stream pages, each N print-stream pages are positioned,
         as specified in section 4.2.9, to create a single impression.
         If a given document does not have N more print-stream pages,
         then the completion of the impression is controlled by the
         "multiple-document-handling" attribute as described in section
         4.2.4; when the value of this attribute is 'single-document' or
         'single-document-new-sheet', the print-stream pages of document
         data from subsequent documents is used to complete the
         impression.

         The size(scaling), position(translation) and rotation of the
         print-stream pages on the impression is implementation defined.
         Note that during this process the print-stream pages may be
         rendered to a form suitable for placing on the impression; this
         rendering is controlled by the values of the "printer-
         resolution" and "print-quality" attributes as described in
         sections 4.2.12 and 4.2.13. In the case N=1, the impression is
         nearly the same as the print-stream page; the differences would
         only be in the size, position and rotation of the print-stream
         page and/or any decoration, such as a frame to the page, that
         is added by the implementation.

      4. The collection of impressions is placed, in sequence, onto
         sides of the media sheets. This placement is controlled by the
         "sides" attribute and the orientation of the print-stream page,
         as described in section 4.2.8. The orientation of the print-
         stream pages affects the orientation of the impression; for
         example, if "number-up" equals 2, then, typically, two portrait
         print-stream pages become one landscape impression. Note that
         the placement of impressions onto media sheets is also
         controlled by the "multiple-document-handling" attribute as
         described in section 4.2.4.

      5. The "copies" and "multiple-document-handling" attributes are
         used to determine how many copies of each media instance are
         created and in what order. See sections 4.2.5 and 4.2.4 for the
         details.

      6. When the correct number of copies are created, the media
         instances are finished according to the values of the
         "finishings" attribute as described in 4.2.6. Note that
         sometimes finishing operations may require manual intervention
         to perform the finishing operations on the copies, especially
         uncollated copies. This document allows any or all of the
         processing steps to be performed automatically or manually at
         the discretion of the Printer object.




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16. APPENDIX E: Generic Directory Schema

   This section defines a generic schema for an entry in a directory
   service.  A directory service is a means by which service users can
   locate service providers.  In IPP environments, this means that IPP
   Printers can be registered (either automatically or with the help of
   an administrator) as entries of type printer in the directory using
   an implementation specific mechanism such as entry attributes, entry
   type fields, specific branches, etc.  Directory clients can search or
   browse for entries of type printer.  Clients use the directory
   service to find entries based on naming, organizational contexts, or
   filtered searches on attribute values of entries.  For example, a
   client can find all printers in the "Local Department" context.
   Authentication and authorization are also often part of a directory
   service so that an administrator can place limits on end users so
   that they are only allowed to find entries to which they have certain
   access rights.  IPP itself does not require any specific directory
   service protocol or provider.

   Note: Some directory implementations allow for the notion of
   "aliasing".  That is, one directory entry object can appear as
   multiple directory entry object with different names for each object.
   In each case, each alias refers to the same directory entry object
   which refers to a single IPP Printer object.

   The generic schema is a subset of IPP Printer Job Template and
   Printer Description attributes (sections 4.2 and 4.4).  These
   attributes are identified as either RECOMMENDED or OPTIONAL for the
   directory entry itself.  This conformance labeling is NOT the same
   conformance labeling applied to the attributes of IPP Printers
   objects.  The conformance labeling in this Appendix is intended to
   apply to directory templates and to IPP Printer implementations that
   subscribe by adding one or more entries to a directory.  RECOMMENDED
   attributes SHOULD be associated with each directory entry.  OPTIONAL
   attributes MAY be associated with the directory entry (if known or
   supported).  In addition, all directory entry attributes SHOULD
   reflect the current attribute values for the corresponding Printer
   object.

   The names of attributes in directory schema and entries SHOULD be the
   same as the IPP Printer attribute names as shown, as much as
   possible.

   In order to bridge between the directory service and the IPP Printer
   object, one of the RECOMMENDED directory entry attributes is the
   Printer object's "printer-uri-supported" attribute.  The directory
   client queries the "printer-uri-supported" attribute (or its
   equivalent) in the directory entry and then the IPP client addresses



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   the IPP Printer object using one of its URIs.  The "uri-security-
   supported" attribute identifies the protocol (if any) used to secure
   a channel.

   The following attributes define the generic schema for directory
   entries of type PRINTER:

     printer-uri-supported              RECOMMENDED    Section 4.4.1
     uri-authentication-supported       RECOMMENDED    Section 4.4.2
     uri-security-supported             RECOMMENDED    Section 4.4.3
     printer-name                       RECOMMENDED    Section 4.4.4
     printer-location                   RECOMMENDED    Section 4.4.5
     printer-info                       OPTIONAL       Section 4.4.6
     printer-more-info                  OPTIONAL       Section 4.4.7
     printer-make-and-model             RECOMMENDED    Section 4.4.9
     ipp-versions-supported             RECOMMENDED    Section 4.4.14
     multiple-document-jobs-supported   OPTIONAL       Section 4.4.16
     charset-supported                  OPTIONAL       Section 4.4.18

     generated-natural-language-
        supported                       OPTIONAL       Section 4.4.20
     document-format-supported          RECOMMENDED    Section 4.4.22
     color-supported                    RECOMMENDED    Section 4.4.26
     compression-supported              RECOMMENDED    Section 4.4.32
     pages-per-minute                   OPTIONAL       Section 4.4.36
     pages-per-minute-color             OPTIONAL       Section 4.4.37

     finishings-supported               OPTIONAL       Section 4.2.6
     number-up-supported                OPTIONAL       Section 4.2.7
     sides-supported                    RECOMMENDED    Section 4.2.8
     media-supported                    RECOMMENDED    Section 4.2.11
     printer-resolution-supported       OPTIONAL       Section 4.2.12
     print-quality-supported            OPTIONAL       Section 4.2.13

17. APPENDIX F:  Differences between the IPP/1.0 and IPP/1.1 "Model and
    Semantics" Documents

   This Appendix is divided into two lists that summarize the
   differences between IPP/1.1 (this document) and IPP/1.0 [RFC2566].
   The section numbers refer to the numbers in this document which in
   some cases have changed from RFC 2566.  When a change affects
   multiple sections, the item is listed once in the order of the first
   section affected and the remaining affected section numbers are
   indicated.







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   The first list contains extensions and clarifications and the second
   list contains changes in semantics or conformance.  However, client
   and IPP object implementations of IPP/1.0 MAY implement any of the
   extensions and clarifications in this document.

   The following extensions and clarifications have been incorporated
   into this document:

      1.  Section 2.1 - clarified that the term "client" can be either
          contained in software controlled by an end user or a part of a
          print server that controls devices.
      2.  Section 2 - clarified that the term "IPP object" and "Printer
          object" can either be embedded in a device object or part of a
          print server that accepts IPP requests.
      3.  Section 2.4 - added the description of the new "uri-
          authentication-supported" Printer Description attribute.
      4.  Section 3.1.3, 3.1.6, 3.2.5.2, and 3.2.6.2 - clarified the
          error handling for operation attributes that have their own
          status code.
      5.  Section 3.1.3 - clarified that multiple occurrences of the
          same attribute in an attribute group is mal-formed.  An IPP
          Printer MAY reject the request or choose one of the
          attributes.
      6.  Section 3.1.6 - reorganized this section into sub-sections to
          separately describe "status-code", "status-message",
          "detailed-status-message", and "document-access-error"
          attributes.
      7.  Section 3.1.6.1 - clarified the error status codes and their
          relationship to operation attributes.
      8.  Section 3.1.6.3 - Added the OPTIONAL "detailed-status-message
          (text(MAX))" operation attribute to provide additional more
          detailed information about a response.
      9.  Section 3.1.6.4 and 3.2.2 - Added the OPTIONAL "document-
          access-error (text(MAX))" operation attribute for use with
          Print-URI and Send-URI responses.
      10. Sections 3.1.7 - Added this new section to clarify returning
          Unsupported Attributes for all operations, including only
          returning attributes that were in the request.  Moved the text
          from section 3.2.1.2 Unsupported Attributes to this section.
      11. Sections 3.1.7 and 4.1 - clarified the encoding of the "out-
          of-band" 'unsupported' and 'unknown' values.
      12. Section 3.1.8 - clarified that only the version number
          parameter will be carried forward into future major or minor
          versions of the protocol.
      13. Section 3.1.8 - relaxed the requirements to increment the
          major version number in future versions of the Model and
          Semantics document.




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      14. Section 3.1.9, and 3.2.5 - added the 'processing' state to the
          list of job states that a job can be in after a Create-Job
          operation.
      15. Section 3.1.9 - clarified that a non-spooling Printer MAY
          accept zero or more subsequent jobs while processing a job and
          flow control them down.  Subsequent create requests are
          rejected with the 'server-error-busy' error status.
      16. Section 3.2.1.1 - clarified the validation of the
          "compression" operation attribute and its relationship to the
          validation of the "document-format" attribute and returning
          Unsupported Attributes.
      17. Sections 3.2.1.1, 4.3.8, 13.1.4.16, and 13.1.4.17 - added the
          'client-error-compression-not-supported', 'client-error-
          compression-error' status codes and the 'unsupported-
          compression' and 'compression-error' job-state-reasons.
      18. Sections 3.2.1.1 and 4.3.8 - added 'unsupported-document-
          format' and 'document-format-error' job-state-reasons.
      19. Sections 3.2.2, 4.3.8 and 13.1.4.19 - added 'client-error-
          document-access-error' status code and 'document-access-error'
          job state reason.
      20. Section 3.2.5.2 and 3.2.6.2 - clarified that the Unsupported
          Attributes group MUST NOT include attributes not requested in
          the Get-Printer-Attributes request.
      21. Section 3.2.6 - clarified that "limit" takes precedence over
          "which-jobs" and "my-jobs'.
      22. Section 3.2.6.2 - clarified that Get-Jobs returns
          'successful-ok' when no jobs to return.
      23. Sections 3.2.7, 3.2.8, and 3.2.9 - added the OPTIONAL Pause-
          Printer, Resume-Printer, and Purge-Jobs operations
      24. Section 3.3.1  - clarified that the authorization required for
          a Send-Document request MUST be the same user as the Create-
          Job or an operator.
      25. Section 3.3.1.1 - clarified that a Create-Job Send-Document
          with "last-document" = 'true' and no data is not an error; its
          a job with no documents.
      26. Sections 3.3.5, 3.3.6, and 3.3.7 - added the OPTIONAL Hold-
          Job, Release-Job, and Restart-Job operations.  Clarified the
          Restart-Job operation so that the Printer MUST re-fetch any
          documents passed by-reference (Print-URI or Send-URI).
      27. Section 4.1 - clarified that the encoding of the out-of-band
          values are specified in the Encoding and Transport" document.
      28. Section 4.1 - Clarified that the requirement that clients MUST
          NOT send "out-of-band" values in requests applies only to
          operations defined in this document.  Other operations are
          allowed to define "out-of-band" values that clients can
          supply.





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      29. Sections 4.1.1 and 4.1.2 - clarified that the maximum 'text'
          and 'name' values of 1023 and 255 are for the
          'textWithoutLanguage' portion of the 'textWithLanguage' form,
          so that the maximum number of octets for the actual text and
          name data is the same for the without and with language forms;
          the 'naturalLanguage' part is in addition.
      30. Section 4.1.9 - clarified that 'mimeMediaType' values can
          include any parameters from the IANA Registry, not just
          charset parameters.
      31. Section 4.1.9.1 - clarified that 'application/octet-stream'
          auto-sensing can happen at create request time and/or
          job/document processing time.
      32. Section 4.1.9.1 - clarified that auto-sensing involves the
          Printer examining some number of octets of document data using
          an implementation-dependent method.
      33. Section 4.1.14 - clarified that the localization of dateTime
          by the client includes the time zone.
      34. Section 4.2 - clarified that xxx-supported have multiple
          keywords and/or names by adding parentheses to the table to
          give:  (1setOf (type3 keyword | name))
      35. Section 4.2.2 - added the 'indefinite' keyword value to the
          "job-hold-until" attribute for use with the create operations
          and Hold-Job and Restart-Job operations.
      36. Section 4.2.6 - added more enum values to the "finishings" Job
          Template attribute.
      37. Section 4.2.6 - clarified that the landscape definition is a
          rotation of the image with respect to the medium.
      38. Section 4.3.7 - added that a forwarding server that cannot get
          any job state MAY return the job's state as 'completed',
          provided that it also return the new 'queued-in-device' job
          state reason.
      39. Section 4.3.7.2 - added the Partitioning of Job States section
          to clarify the concepts of Job Retention, Job History, and Job
          Removal.
      40. Section 4.3.8 - added 'job-data-insufficient' job state reason
          to indicate whether sufficient data has arrived for the
          document to start to be processed.
      41. Section 4.3.8 - added 'document-access-error' job state reason
          to indicate an access error of any kind.
      42. Section 4.3.8 - added 'job-queued-for-marker' job state reason
          to indicate whether the job has completed some processing and
          is waiting for the marker.
      43. Section 4.3.8 - added 'unsupported-compression' and
          'compression-error' job state reasons to indicate compression
          not supported or compression processing error after the create
          has been accepted.





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      44. Section 4.3.8 - added 'unsupported-document-format' and
          'document-format-error' job state reasons to indicate document
          not supported or document format processing error after the
          create has been accepted.
      45. Section 4.3.8 - added 'queued-in-device' job state reason to
          indicate that a job as been forwarded to a print system or
          device that does not provide any job status.
      46. Section 4.3.10 - added "job-detailed-status-messages (1setOf
          text(MAX)) for returning detailed error messages.
      47. Section 4.3.11 - added the "job-document-access-errors (1setOf
          text(MAX))
      48. Section 4.3.14.2 - clarified that the time recorded is the
          first time processing since the create operation or the
          Restart-Job operation.
      49. Section 4.3.14.2 and 4.3.14.3 - clarified that the out-of-band
          value 'no-value' is returned if the job has not started
          processing or has not completed, respectively.
      50. Section 4.3.14 - Added the OPTIONAL "date-time-at-creation",
          "date-time-at-processing", and "date-time-at-completed" Event
          Time Job Description attributes
      51. Section 4.4.3 - added the 'tls' value to "uri-security-
          supported" attribute.
      52. Section 4.4.3 - clarified "uri-security-supported" is
          orthogonal to Client Authentication so that 'none' does not
          exclude Client Authentication.
      53. Section 4.4.11 - simplified the "printer-state" descriptions
          while generalizing to allow high end devices that interpret
          one or more jobs while marking another.  Indicated that
          'spool-area-full' and 'stopped-partly' "printer-state-reasons"
          may be used to provide further state information.
      54. Section 4.4.12 - added the 'moving-to-paused' keyword value to
          the "printer-state-reasons" attribute for use with the Pause-
          Printer operation.
      55. Section 4.4.12 - replaced the duplicate 'marker-supply-low'
          keyword with the missing 'toner-empty' keyword for the
          "printer-state-reasons" attribute.  (This correction was also
          made before RFC 2566 was published).
      56. Section 4.4.12 - clarified 'spool-area-full' "printer-state-
          reasons" to include non-spooling printers to indicate when it
          can and cannot accept another job.
      57. Section 4.4.15 - added the enum values to the "operations-
          supported" attribute for the new operations.  Clarified that
          the values of this attribute are encoded as any enum, namely
          32-bit values.
      58. Section 4.4.30 - clarified that the dateTime value of
          "printer-current-time" is on a "best efforts basis".  If a
          proper date-time cannot be obtained, the implementation
          returns the 'no-value' out-of-band value.  Also clarified that



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          the time zone NEED NOT be the time zone that the people near
          the device use and that the client SHOULD display the dateTime
          attributes in the user's local time.
      59. Sections 4.4.36 and 4.4.37 - added the OPTIONAL "pages-per-
          minute" and "pages-per-minute-color" Printer Description
          attributes.
      60. Section 5.1 - clarified that the client conformance
          requirements apply to clients controlled by an end user and
          clients in servers.
      61. Section 5.1 - clarified that any response MAY contain
          additional attribute groups, attributes, attribute syntaxes,
          or attribute values.
      62. Section 5.1 - clarified that a client SHOULD do its best to
          prevent a channel from being closed by a lower layer when the
          channel is flow controlled off by the IPP Printer.
      63. Section 5.2 - clarified that the IPP object requirements apply
          to objects embedded in devices or that are parts of servers.
      64. Section 5.2.2 - clarified that IPP objects MAY return
          operation responses that contain attribute groups, attribute
          names, attribute syntaxes, attribute values, and status codes
          that are extensions to this standard.
      65. Section 6 - changed the terminology of "private extensions" to
          "vendor extensions" and indicated that they are registered
          with IANA along with IETF standards track extensions.
      66. Section 6.7 - inserted this section on registering out-of-band
          attribute values with IANA as extensions.
      67. Section 8.3 - clarified the use of URIs for each Client
          Authentication mechanism.
      68. Section 8.5 - added the security discussion around the new
          operator/administrator operations.
      69. Section 13.1.4.16 - added client-error-compression-not-
          supported (0x040F)
      70. Section 13.1.4.17 - added client-error-compression-error
          (0x0410)
      71. Section 13.1.4.18 - added client-error-document-format-error
          (0x0411)
      72. Section 13.1.4.19 - added client-error-document-access-error
          (0x0412)
      73. Section 13.1.5.10 - added server-error-multiple-document-
          jobs-not-supported (0x0509)
      74. Section 14 - added 'a-white', 'b-white', 'c-white', 'd-white',
          and 'e-white' and clarified that the existing 'a', 'b', 'c',
          'd', and 'e' values are size values.  Added American,
          Japanese, and European Engineering sizes, filled out
          -transparent and - translucent media names and drawings for
          the synchro cut sizes.





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      75. Section 16 - softened the RECOMMENDATION for IPP Printer
          attributes in a Directory schema so that they can have
          equivalents.
      76. Section 16 - added the OPTIONAL "pages-per-minute" and
          "pages-per-minute-color" Printer attributes to the Directory
          schema.
      77. Section 16 - added OPTIONAL "multiple-document-jobs-supported"
          to the Directory schema.
      78. Section 16 - added RECOMMENDED "uri-authentication-supported",
          "ipp-versions-supported", and "compression-supported" to the
          Directory schema.

   The following changes in semantics and/or conformance have been
   incorporated into this document:

      1.  Section 3.1.6.3 - allowed a Printer to localize the
          "detailed-status-message" operation response attribute, but
          indicated that such localization might obscure the technical
          meaning of such messages.
      2.  Section 3.1.8, 5.2.4, and 13.1.5.4 - Clients and IPP objects
          MUST support version 1.1 conformance requirements.   It is
          recommended that they interoperate with 1.0.  Also clarified
          that IPP Printers MUST accept '1.1' requests.   It is
          recommended that they also accept '1.x' requests.

      3.  Section 3.2.1.1 and section 4.4.32 - changed the "compression"
          operation and the "compression-supported" Printer Description
          attribute from OPTIONAL to REQUIRED.
      4.  Sections 3.2.1.2 and 4.3.8 - changed "job-state-reasons" from
          RECOMMENDED to REQUIRED, so that "job-state-reasons" MUST be
          returned in create operation responses.
      5.  Sections 3.2.4, 3.3.1, 4.4.16, and 16 - changed Create-
          Job/Send-Document so that they MAY be implemented while only
          supporting one document jobs.  Added the "multiple-document-
          jobs-supported" boolean Printer Description attribute to
          indicate whether Create-Job/Send-Document support multiple
          document jobs or not.  Added to the Directory schema.
      6.  Section 4.1.9 - deleted 'text/plain; charset=iso-10646-ucs-2',
          since binary is not legal with the 'text' type.
      7.  Section 4.1.9.1 - added the RECOMMENDATION that a Printer
          indicate by printing on the job's job-start-sheet that auto-
          sensing has occurred and what document format was auto-sensed.
      8.  Section 4.2.4 - indicated that the "multiple-document-
          handling" Job Template attribute MUST be supported with at
          least one value if the Printer supports multiple documents per
          job





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      9.  Section 4.3.7.2 - indicated that the 'job-restartable' job
          state reason SHOULD be supported if the Restart-Job operation
          is supported.
      10. Section 4.3.8 - changed "job-state-reasons" from RECOMMENDED
          to REQUIRED.
      11. Section 4.3.8 - clarified the conformance of the values of the
          "job-state-reasons" attribute by copying conformance
          requirements from other sections of the document so that it is
          clear from reading the definition of "job-state-reasons" which
          values MUST or SHOULD be supported.  The 'none',
          'unsupported-compression', and 'unsupported-document-format'
          values MUST be supported.  The 'job-hold-until-specified'
          SHOULD be specified if the "job-hold-until" Job Template is
          supported.  The following values SHOULD be supported:  'job-
          canceled-by-user', 'aborted-by-system', and 'job-completed-
          successfully'.  The
          'job-canceled-by-operator' SHOULD be supported if the
          implementation permits canceling by other than the job owner.
          The 'job-canceled-at-device' SHOULD be supported if the device
          supports canceling jobs at the console.  The 'job-completed-
          with-warnings' SHOULD be supported, if the implementation
          detects warnings.  The 'job-completed-with-errors' SHOULD be
          supported if the implementation detects errors.  The 'job-
          restartable' SHOULD be supported if the Restart-Job operation
          is supported.
      12. Section 4.3.10 - allowed a Printer to localize the "job-
          detailed-status-message" Job Description attribute, but
          indicated that such localization might obscure the technical
          meaning of such messages.
      13. Section 4.3.14 - changed the "time-at-creation", "time-at-
          processing", and "time-at-completed" Event Time Job
          Description attributes from OPTIONAL to REQUIRED.
      14. Section 4.3.14.4 - added the REQUIRED "job-printer-up-time
          (integer(1:MAX))" Job Description attribute as an alias for
          "printer-up-time" to reduce number of operations to get job
          times.
      15. Section 4.4.2 - added the REQUIRED "uri-authentication-
          supported (1setOf type2 keyword)" Printer Description
          attribute to describe the Client Authentication used by each
          Printer URI.
      16. Section 4.4.12 - changed "printer-state-reasons" Printer
          Description attribute from OPTIONAL to REQUIRED.
      17. Section 4.4.12 - changed 'paused' value of "printer-state-
          reasons" to MUST if Pause-Printer operation is supported.







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      18. Section 4.4.14 - added the REQUIRED "ipp-versions-supported
          (1setOf keyword)" Printer Description attribute, since IPP/1.1
          Printers do not have to support version '1.0' conformance
          requirements.  Section 4.4.16 - added the "multiple-document-
          jobs-supported (boolean)" Printer Description attribute so
          that a client can tell whether a Printer that supports
          Create-Job/Send-Document supports multiple document jobs or
          not.  This attribute is REQUIRED if the Create-Job operation
          is supported.
      19. Section 4.4.24 - changed the "queued-job-count" Printer
          Description attribute from RECOMMENDED to REQUIRED.
      20. Section 4.4.32 - changed "compression-supported (1setOf type3
          keyword)" Printer Description attribute from OPTIONAL to
          REQUIRED.
      21. Section 5.1 - changed the client security requirements from
          RECOMMENDED non-standards track SSL3 to MUST support Client
          Authentication as defined in the IPP/1.1 Encoding and
          Transport document [RFC2910].  A client SHOULD support
          Operation Privacy and Server Authentication as defined in the
          IPP/1.1 Encoding and Transport document [RFC2910].
      22. Section 5.2.7 - changed the IPP object security requirements
          from OPTIONAL non-standards track SSL3 to SHOULD contain
          support for Client Authentication as defined in the IPP/1.1
          Encoding and Transport document [RFC2910].  A Printer
          implementation MAY allow an administrator to configure the
          Printer so that all, some, or none of the users are
          authenticated.  An IPP Printer implementation SHOULD contain
          support for Operation Privacy and Server Authentication as
          defined in the IPP/1.1 Encoding and Transport document
          [RFC2910].  A Printer implementation MAY allow an
          administrator to configure the degree of support for Operation
          Privacy and Server Authentication.  Security MUST NOT be
          compromised when the client supplies a lower version-number in
          a request.
      23. Section 14 (Appendix C): Corrected typo, changing the keyword
          'iso-10-white' to 'iso-a10-white'.

   See also the "IPP/1.1 Encoding and Transport" [RFC2910] document for
   differences between IPP/1.0 [RFC2565] and IPP/1.1 [RFC2910].












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18.  Full Copyright Statement

   Copyright (C) The Internet Society (2000).  All Rights Reserved.

   This document and translations of it may be copied and furnished to
   others, and derivative works that comment on or otherwise explain it
   or assist in its implementation may be prepared, copied, published
   and distributed, in whole or in part, without restriction of any
   kind, provided that the above copyright notice and this paragraph are
   included on all such copies and derivative works.  However, this
   document itself may not be modified in any way, such as by removing
   the copyright notice or references to the Internet Society or other
   Internet organizations, except as needed for the purpose of
   developing Internet standards in which case the procedures for
   copyrights defined in the Internet Standards process must be
   followed, or as required to translate it into languages other than
   English.

   The limited permissions granted above are perpetual and will not be
   revoked by the Internet Society or its successors or assigns.

   This document and the information contained herein is provided on an
   "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING
   TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING
   BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION
   HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF
   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.

Acknowledgement

   Funding for the RFC Editor function is currently provided by the
   Internet Society.



















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