INTERNET-DRAFT
draft-ietf-ipp-model-08.txt
draft-ietf-ipp-model-09.txt
                                                              R. deBry
                                                       IBM Corporation
                                                           T. Hastings
                                                     Xerox Corporation
                                                            R. Herriot
                                                      Sun Microsystems
                                                           S. Isaacson
                                                          Novell, Inc.
                                                             P. Powell
                                            San Diego State University
                                                     December 19, 1997
                                                      January 16, 1998

         Internet Printing Protocol/1.0: Model and Semantics
   Copyright (C) The Internet Society (date). All Rights Reserved.

Status of this Memo

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This Internet-Draft expires on June 19, July 16, 1997.

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.  The protocol 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 1.0 (IPP/1.0)
focuses only on end user functionality.

                        Expires June 19, July 16, 1998

The full set of IPP documents includes:

  Requirements for an Internet Printing Protocol [IPP-REQ]
  Rationale for the Structure and Model and Protocol for the Internet
     Printing Protocol [IPP-RAT]
  Internet Printing Protocol/1.0: Model and Semantics (this document)
  Internet Printing Protocol/1.0: Protocol Specification [IPP-PRO]

The requirements document, "Requirements for an Internet Printing
Protocol", 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.  The requirements document calls
out a subset of end user requirements that MUST be satisfied in
IPP/1.0.  Operator and administrator requirements are out of scope for
version 1.0.  The rationale document, "Rationale for the Structure and
Model and Protocol for the Internet Printing Protocol", describes IPP
from a high level view, defines a roadmap for the various documents
that form the suite of IPP specifications, and gives background and
rationale for the IETF working group's major decisions.  This
document, "Internet Printing Protocol/1.0: Model and Semantics",
describes a simplified model with abstract objects, their attributes,
and their operations.  The model introduces a Printer and a Job.  The
Job supports multiple documents per Job.  The model document also
addresses how security, internationalization, and directory issues are
addressed.  The protocol specification, " Internet Printing
Protocol/1.0: Protocol Specification", is a formal mapping of the
abstract operations and attributes defined in the model document onto
HTTP/1.1.  The protocol specification defines the encoding rules for a
new Internet media type called "application/ipp".

                        Expires June 19, July 16, 1998

Table of Contents

1.  Introduction ...................................................9 ...................................................8
1.1  Simplified Printing Model.....................................10
2.  IPP Objects ...................................................13 ...................................................12
2.1  Printer Object................................................14 Object................................................13
2.2  Job Object....................................................15 Object....................................................14
2.3  Object Relationships..........................................16 Relationships..........................................15
2.4  Object Identity...............................................17 Identity...............................................16
3.  IPP Operations ................................................18 ................................................19
3.1  Common Semantics..............................................19 Semantics..............................................20
3.1.1     Operation Characteristics................................19 IDs and Request IDs............................20
3.1.2     Operation Targets........................................21     Attributes...............................................21
3.1.3     Operation Targets........................................22
3.1.4     Character Set and Natural Language Operation Attributes..22
3.1.3.1 Attributes..23
3.1.4.1     Request Operation Attributes ..........................22
3.1.3.2 ..........................24
3.1.4.2     Response Operation Attributes .........................25
3.1.4 .........................26
3.1.5     Operation Status Codes and Messages......................26
3.1.5     Versions.................................................27 Messages......................27
3.1.6     Versions.................................................28
3.1.7     Job Creation Operations..................................29 Operations..................................30
3.2  Printer Operations............................................31 Operations............................................32
3.2.1     Print-Job Operation......................................31 Operation......................................32
3.2.1.1     Print-Job Request .....................................31 .....................................32
3.2.1.2     Print-Job Response ....................................35 ....................................36
3.2.2     Print-URI Operation......................................37 Operation......................................39
3.2.3     Validate-Job Operation...................................38 Operation...................................39
3.2.4     Create-Job Operation.....................................38 Operation.....................................40
3.2.5     Get-Printer-Attributes Operation.........................39 Operation.........................40
3.2.5.1     Get-Printer-Attributes Request ........................39 ........................41
3.2.5.2     Get-Printer-Attributes Response .......................41 .......................43
3.2.6     Get-Jobs Operation.......................................42 Operation.......................................43
3.2.6.1     Get-Jobs Request ......................................42 ......................................44
3.2.6.2     Get-Jobs Response .....................................44 .....................................45
3.3  Job Operations................................................45 Operations................................................47
3.3.1     Send-Document Operation..................................45 Operation..................................47
3.3.1.1     Send-Document Request .................................46 .................................48
3.3.1.2     Send-Document Response ................................48 ................................50
3.3.2     Send-URI Operation.......................................48 Operation.......................................50
3.3.3     Cancel Job Operation.....................................49 Operation.....................................51
3.3.3.1     Cancel-Job Request ....................................49 ....................................51
3.3.3.2     Cancel-Job Response ...................................49 ...................................52
3.3.4     Get-Job-Attributes Operation.............................50 Operation.............................52
3.3.4.1     Get-Job-Attributes Request ............................51 ............................53
3.3.4.2     Get-Job-Attributes Response ...........................51 ...........................54
4.  Object Attributes .............................................52 .............................................54
4.1  Attribute Syntaxes............................................53 Syntaxes............................................55
4.1.1     'text'...................................................54     'text'...................................................56
4.1.2     'textWithLanguage'.......................................54
4.1.3     'name'...................................................56     'textWithLanguage'.......................................57

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4.1.3     'name'...................................................58
4.1.4     'nameWithLanguage'.......................................56     'nameWithLanguage'.......................................58
4.1.5     'keyword'................................................56     'keyword'................................................59
4.1.6     'enum'...................................................57     'enum'...................................................60
4.1.7     'uri'....................................................58     'uri'....................................................60
4.1.8     'uriScheme'..............................................58     'uriScheme'..............................................60
4.1.9     'charset'................................................58     'charset'................................................61
4.1.10    'naturalLanguage'........................................59    'naturalLanguage'........................................62
4.1.11    'mimeMediaType'..........................................60    'mimeMediaType'..........................................62
4.1.12    'octetString'............................................61    'octetString'............................................63
4.1.13    'boolean'................................................61    'boolean'................................................64
4.1.14    'integer'................................................61    'integer'................................................64
4.1.15    'rangeOfInteger'.........................................62    'rangeOfInteger'.........................................64
4.1.16    'dateTime'...............................................62    'dateTime'...............................................64
4.1.17    'resolution'.............................................62    'resolution'.............................................64
4.1.18    '1setOf  X'..............................................63  X'..............................................65
4.2  Job Template Attributes.......................................63 Attributes.......................................65
4.2.1     job-priority (integer(1:100))............................67 (integer(1:100))............................69
4.2.2     job-hold-until (type4 keyword | name (MAX))..............68 (MAX))..............70
4.2.3     job-sheets (type4 keyword | name(MAX))...................69 name(MAX))...................71
4.2.4     multiple-document-handling (type2 keyword)...............70 keyword)...............71
4.2.5     copies (integer(1:MAX))..................................71 (integer(1:MAX))..................................73
4.2.6     finishings (1setOf type2 enum)...........................71 enum)...........................73
4.2.7     page-ranges (1setOf rangeOfInteger (1:MAX))..............72 (1:MAX))..............74
4.2.8     sides (type2 keyword)....................................73 keyword)....................................75
4.2.9     number-up (integer(1:MAX))...............................74 (integer(1:MAX))...............................75
4.2.10    orientation    orientation-requested (type2 enum).................................74 enum).......................76
4.2.11    media (type4 keyword | name(MAX))........................75 name(MAX))........................77
4.2.12    printer-resolution (resolution)..........................76 (resolution)..........................78
4.2.13    print-quality (type2 enum)...............................76 enum)...............................78
4.3  Job Description Attributes....................................76 Attributes....................................79
4.3.1     job-uri (uri)............................................79 (uri)............................................81
4.3.2     job-id (integer(1:MAX))..................................79 (integer(1:MAX))..................................81
4.3.3     job-more-info (uri)......................................79     job-printer-uri (uri)....................................81
4.3.4     job-name (name(MAX)).....................................79     job-more-info (uri)......................................82
4.3.5     job-originating-user-name (name(MAX))....................80     job-name (name(MAX)).....................................82
4.3.6     job-originating-user-name (name(MAX))....................82
4.3.7     job-state (type1 enum)...................................80
4.3.7 enum)...................................83
4.3.8     job-state-reasons (1setOf  type2 keyword)................83
4.3.8     job-state-message (text(MAX))............................85 keyword)................85
4.3.9     number-of-documents (integer(0:MAX)).....................86     job-state-message (text(MAX))............................88
4.3.10    containing-printer-uri (uri).............................86    number-of-documents (integer(0:MAX)).....................88
4.3.11    output-device-assigned (name(127)).......................86 (name(127)).......................88
4.3.12    time-at-creation (integer(0:MAX))........................86 (integer(0:MAX))........................89
4.3.13    time-at-processing (integer(0:MAX))......................87 (integer(0:MAX))......................89
4.3.14    time-at-completed (integer(0:MAX)).......................87 (integer(0:MAX)).......................89
4.3.15    number-of-intervening-jobs (integer(0:MAX))..............87 (integer(0:MAX))..............89
4.3.16    job-message-from-operator (text(127))....................87 (text(127))....................89
4.3.17    compression (type3 keyword)..............................87
4.3.18    job-k-octets (integer(0:MAX))............................88 (integer(0:MAX))............................90

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4.3.19

4.3.18    job-impressions (integer(0:MAX)).........................88
4.3.20 (integer(0:MAX)).........................90
4.3.19    job-media-sheets (integer(0:MAX))........................89
4.3.21 (integer(0:MAX))........................91
4.3.20    job-k-octets-processed (integer(0:MAX))..................89
4.3.22 (integer(0:MAX))..................91
4.3.21    job-impressions-completed (integer(0:MAX))...............90
4.3.23 (integer(0:MAX))...............92
4.3.22    job-media-sheets-completed (integer(0:MAX))..............90
4.3.24 (integer(0:MAX))..............92
4.3.23    attributes-charset (charset).............................90
4.3.25 (charset).............................92
4.3.24    attributes-natural-language (naturalLanguage)............91 (naturalLanguage)............93
4.4  Printer Description Attributes................................91 Attributes................................93
4.4.1     printer-uri (uri)........................................93     printer-uri-supported (uri)..............................95
4.4.2     printer-tls-uri (uri)....................................93     uri-security-supported (1setOf type2 keyword)............95
4.4.3     printer-name (name(127)).................................94 (name(127)).................................97
4.4.4     printer-location (text(127)).............................94 (text(127)).............................97
4.4.5     printer-info (text(127)).................................95 (text(127)).................................97
4.4.6     printer-more-info (uri)..................................95 (uri)..................................98
4.4.7     printer-driver-installer (uri)...........................95 (uri)...........................98
4.4.8     printer-make-and-model (text(127)).......................95 (text(127)).......................98
4.4.9     printer-more-info-manufacturer (uri).....................95 (uri).....................98
4.4.10    printer-state (type1 enum)...............................96 enum)...............................98
4.4.11    printer-state-reasons (1setOf type2 keyword).............97 keyword)............100
4.4.12    printer-state-message (text(MAX))........................99 (text(MAX)).......................102
4.4.13    operations-supported (1setOf type2 enum)................100 enum)................102
4.4.14    charset-configured (charset)............................100 (charset)............................103
4.4.15    charset-supported (1setOf charset)......................101 charset)......................103
4.4.16    natural-language-configured (naturalLanguage)...........101 (naturalLanguage)...........104
4.4.17    generated-natural-language-supported (1setOf
          naturalLanguage)........................................101
          naturalLanguage)........................................104
4.4.18    document-format-default (mimeMediaType).................102 (mimeMediaType).................105
4.4.19    document-format-supported (1setOf mimeMediaType)........102 mimeMediaType)........105
4.4.20    printer-is-accepting-jobs (boolean).....................102 (boolean).....................105
4.4.21    queued-job-count (integer(0:MAX)).......................103 (integer(0:MAX)).......................105
4.4.22    printer-message-from-operator (text(127))...............103 (text(127))...............106
4.4.23    color-supported (boolean)...............................103 (boolean)...............................106
4.4.24    reference-uri-schemes-supported (1setOf uriScheme)......103 uriScheme)......106
4.4.25    pdl-override    pdl-override-supported (type2 keyword)............................104 keyword)..................106
4.4.26    printer-up-time (integer(1:MAX))........................104 (integer(1:MAX))........................107
4.4.27    printer-current-time (dateTime).........................105 (dateTime).........................107
4.4.28    multiple-operation-time-out (integer(1:MAX))............105 (integer(1:MAX))............108
4.4.29    compression-supported (1setOf type3 keyword)............108
4.4.30    job-k-octets-supported (rangeOfInteger(0:MAX))..........108
4.4.31    job-impressions-supported (rangeOfInteger(0:MAX)).......108
4.4.32    job-media-sheets-supported (rangeOfInteger(0:MAX))......109
5.  Conformance ..................................................105 ..................................................109
5.1  Client Conformance Requirements..............................105 Requirements..............................109
5.2  IPP Object Conformance Requirements..........................106 Requirements..........................110
5.2.1     Objects.................................................106     Objects.................................................110
5.2.2     Operations..............................................106     Operations..............................................110
5.2.3     IPP Object Attributes...................................107 Attributes...................................111
5.2.4     Extensions..............................................107     Extensions..............................................111

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5.2.5     Attribute Syntaxes......................................107 Syntaxes......................................111
5.3  Charset and Natural Language Requirements....................108 Requirements....................111
5.4  Security Conformance Requirements............................108 Requirements............................112
6.  IANA Considerations (registered and private extensions) ......108

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6.1  Typed Extensions.............................................108 Extensions.............................................112
6.2  Registration of MIME types/sub-types for document-formats....110 document-formats....114
6.3  Attribute Extensibility......................................110 Extensibility......................................114
6.4  Attribute Syntax Extensibility...............................110 Extensibility...............................115
7.  Internationalization Considerations ..........................111 ..........................115
8.  Security Considerations ......................................113 ......................................118
8.1  Security Scenarios...........................................115 Scenarios...........................................119
8.1.1     Client and Server in the Same Security Domain...........115 Domain...........119
8.1.2     Client and Server in Different Security Domains.........115 Domains.........119
8.1.3     Print by Reference......................................116 Reference......................................120
8.2  URIs for TLS and non-TLS access..............................116 Access..............................120
8.3  The "requesting-user-name" Operation Attribute...............116 Attribute...............120
8.4  Restricted Queries...........................................118 Queries...........................................122
8.5  IPP Security Application Profile for TLS.....................118 TLS.....................122
9.  References ...................................................118 ...................................................123
10. Copyright Notice .............................................121 .............................................126
11. Author's Address .............................................122 .............................................126
12. APPENDIX A: Terminology ......................................125 ......................................130
12.1 Conformance Terminology......................................125 Terminology......................................130
12.1.1    MUST....................................................125    MUST....................................................130
12.1.2    MUST NOT................................................125 NOT................................................130
12.1.3    SHOULD..................................................125    SHOULD..................................................130
12.1.4    SHOULD NOT..............................................125 NOT..............................................130
12.1.5    MAY.....................................................126    MAY.....................................................131
12.1.6    NEED NOT................................................126 NOT................................................131
12.2 Model Terminology............................................126 Terminology............................................131
12.2.1    Keyword.................................................126    Keyword.................................................131
12.2.2    Attributes..............................................126    Attributes..............................................131
12.2.2.1    Attribute Name .......................................127 .......................................132
12.2.2.2    Attribute Group Name .................................127 .................................132
12.2.2.3    Attribute Value ......................................127 ......................................132
12.2.2.4    Attribute Syntax .....................................127 .....................................132
12.2.3    Supports................................................127    Supports................................................132
12.2.4    print-stream page.......................................129 page.......................................134
12.2.5    impression..............................................130    impression..............................................135
13. APPENDIX B:  Status Codes and Suggested Status Code Messages .130 .135
13.1 Status Codes.................................................131 Codes.................................................136
13.1.1    Informational...........................................131    Informational...........................................136
13.1.2    Successful Status Codes.................................131 Codes.................................136
13.1.2.1    successful-ok (0x0000) ...............................131 ...............................136
13.1.2.2    successful-ok-ignored-or-substituted-
            attributes    successful-ok-ignored-or-substituted-attributes
            (0x0001) ..................................132 .............................................137
13.1.2.3    successful-ok-conflicting-attributes (0x0002) ........132 ........137
13.1.3    Redirection Status Codes................................132 Codes................................137

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13.1.4    Client Error Status Codes...............................132 Codes...............................137
13.1.4.1    client-error-bad-request (0x0400) ....................132 ....................137
13.1.4.2    client-error-forbidden (0x0401) ......................132 ......................137
13.1.4.3    client-error-not-authenticated (0x0402) ..............133

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13.1.4.4    client-error-not-authorized (0x0403) .................133 .................138
13.1.4.5    client-error-not-possible (0x0404) ...................133 ...................138
13.1.4.6    client-error-timeout (0x0405) ........................133 ........................138
13.1.4.7    client-error-not-found (0x0406) ......................134 ......................139
13.1.4.8    client-error-gone (0x0407) ...........................134 ...........................139
13.1.4.9    client-error-request-entity-too-large (0x0408) .......134 .......139
13.1.4.10   client-error-request-uri-too-long (0x0409) ...........135 ...........140
13.1.4.11   client-error-document-format-not-supported (0x040A) ..135 ..140
13.1.4.12   client-error-attributes-or-values-not-
            supported   client-error-attributes-or-values-not-supported
            (0x040B) ...................................135 .............................................140
13.1.4.13   client-error-uri-scheme-not-supported (0x040C) .......136 .......141
13.1.4.14   client-error-charset-not-supported (0x040D) ..........136 ..........141
13.1.4.15   client-error-conflicting-attributes (0x040E) .........136 .........141
13.1.5    Server Error Status Codes...............................136 Codes...............................141
13.1.5.1    server-error-internal-error (0x0500) .................136 .................141
13.1.5.2    server-error-operation-not-supported (0x0501) ........136 ........141
13.1.5.3    server-error-service-unavailable (0x0502) ............137 ............142
13.1.5.4    server-error-version-not-supported (0x0503) ..........137 ..........142
13.1.5.5    server-error-device-error (0x0504) ...................137 ...................142
13.1.5.6    server-error-temporary-error (0x0505) ................138 ................143
13.1.5.7    server-error-not-accepting-jobs (0x0506) .............138 .............143
13.2 Status Codes for IPP Operations..............................139 Operations..............................144
14. APPENDIX C:  "media" keyword values ..........................139 ..........................144
15. APPENDIX D: Processing IPP Attributes ........................144 ........................149
15.1 Fidelity.....................................................145 Fidelity.....................................................150
15.2 Page Description Language (PDL) Override.....................146 Override.....................151
15.3 Suggested Operation Processing Steps for All Operations......148 Operations......153
15.3.1    Validate version number.................................148 number.................................153
15.3.2    Validate operation code.................................149 identifier...........................154
15.3.3    Validate the request identifier.........................154
15.3.4    Validate attribute group and attribute presence and
          order...................................................149
15.3.3.1
          order...................................................154
15.3.4.1    Validate the presence and order of attribute groups ..149
15.3.3.2 ..155
15.3.4.2    Ignore unknown attribute groups in the expected
            position .............................................150
15.3.3.3 .............................................155
15.3.4.3    Validate the presence of a single occurrence of
            required Operation attributes ........................150
15.3.4 ........................156
15.3.5    Validate the values of the MANDATORY Operation
          attributes..............................................156
15.3.5
          attributes..............................................161
15.3.6    Validate the values of the OPTIONAL Operation
          attributes..............................................159
          attributes..............................................164
15.4 Suggested Additional Processing Steps for Operations that
     Create/Validate Jobs and add Documents..................161 Add Documents.......................166
15.4.1    Default "ipp-attribute-fidelity" if not supplied........161 supplied........166

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15.4.2    Check that the Printer object is accepting jobs.........167
15.4.3    Validate the values of the Job Template attributes......161
15.4.3 attributes......167
15.4.4    Check for conflicting Job Template attributes values....166
15.4.4 values....171
15.4.5    Decide whether to REJECT the request....................167
15.4.5 request....................172
15.4.6    For the Validate-Job operation, RETURN one of the
          success status codes................................167

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15.4.6 codes....................................172
15.4.7    Create the Job object with attributes to support........167
15.4.7 support........173
15.4.8    Return one of the success status codes..................169
15.4.8 codes..................174
15.4.9    Accept appended Document Content........................170
15.4.9 Content........................175
15.4.10   Scheduling and Starting to Process the Job..............170
15.4.10 Job..............175
15.4.11   Completing the Job......................................170
15.4.11 Job......................................175
15.4.12   Destroying the Job after completion.....................170
15.4.12 completion.....................175
15.4.13   Interaction with "ipp-attribute-fidelity"...............170 "ipp-attribute-fidelity"...............176
15.5 Using Job Template Attributes During Document Processing.....171 Processing.....176
16. APPENDIX E: Generic Directory Schema .........................172

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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 1.0 (IPP/1.0) focuses only on end user
functionality.  This document is just one of a suite of documents that
fully define IPP.  The full set of IPP documents includes:

  Requirements for an Internet Printing Protocol [IPP-REQ]
  Rationale for the Structure and Model and Protocol for the Internet
     Printing Protocol [IPP-RAT]
  Internet Printing Protocol/1.0: Model and Semantics (this document)
  Internet Printing Protocol/1.0: Protocol Specification [IPP-PRO]

Anyone reading this document for the first time is strongly encouraged
to read the IPP documents in the following order:

  1. The requirements document, "Requirements for an Internet
     Printing Protocol".  That 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.  The requirements document calls out a subset of
     end user requirements that MUST be satisfied in IPP/1.0.
     Operator and administrator requirements are out of scope for
     version 1.0.
  2. The rationale document, "Rationale for the Structure and Model
     and Protocol for the Internet Printing Protocol".  That document
     describes IPP from a high level view, defines a roadmap for the
     various documents that form the suite of IPP specifications, and

                        Expires July 16, 1998
     gives background and rationale for the IETF working group's major
     decisions.
  3. This document, the "Internet Printing Protocol/1.0: Model and
     Semantics" document.  It describes a simplified model with
     abstract objects, their attributes, and their operations.  The
     model introduces a Printer and a Job.  The Job supports multiple
     documents per Job.  The model document also addresses how
     security, internationalization, and directory issues are
     addressed.
  4. The protocol specification, " Internet Printing Protocol/1.0:
     Protocol Specification".  That document is a formal mapping of
     the abstract operations and attributes defined in the model
     document onto HTTP/1.1.  The protocol specification defines the
     encoding rules for a new Internet media type called
     "application/ipp".

                        Expires June 19, 1998

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 in the model and their
     basic behaviors, attributes, and interactions.
  - Section 3 defines the operations supported by IPP/1.0.  IPP
     operations are synchronous, therefore, for each operation, there
     is a both request and a and 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, Copyright Notice, and
     Author contact information.
  - Sections 12 - 14 are appendices that cover Terminology, Status
     Codes and Messages, and "media" keyword values.  This document
     uses terms such as "attributes", "keywords", and "support".
     These terms have special meaning and are defined in the model
     terminology section. Capitalized terms such as MANDATORY, SHALL,
     and OPTIONAL have special meaning relating to conformance.  These
     terms are defined in the section on conformance terminology, most
     of which is taken from RFC 2119 [RFC2119].
  - Section 15 is an appendix that defines the rules and suggested
     techniques for the processing by IPP object of attributes in client requests. requests by
     IPP objects.  This section helps to clarify the affects of
     interactions between significant related attributes and their values.
  - Section 16 is an appendix that enumerates a subset of Printer
     attributes that form a generic directory schema.  These
     attributes are useful when registering a Printer so that a client

                        Expires July 16, 1998
     can find the Printer not just by name, but by filtered searches
     as well.

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/1.0).  IPP/1.0
incorporates many of the relevant ideas and lessons learned from other
specification and development efforts [HTPP] [ISO10175] [LDPA]
[P1387.4] [PSIS] [RFC1179] [SWP].

                        Expires June 19, 1998

The IPP/1.0 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).

The terminology used in the remainder of this document is defined in
section 12.  In the remainder of this document, terms such as
"attributes", "keywords", and "support" have special meaning and are
defined in the model terminology section. Capitalized terms such as
MANDATORY, SHALL, and OPTIONAL have special meaning relating to
conformance.  These terms are defined in the section on conformance
terminology, most of which is taken from RFC 2119 [RFC2119].

It is important, however, to understand that in real system
implementations (which lie underneath the abstracted IPP/1.0 model),
there are other components of a print service which are not explicitly
defined in the IPP/1.0 model. The following figure illustrates where
IPP/1.0 fits with respect to these other components.

                        Expires June 19, July 16, 1998
                             +--------------+
                             |  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 is directly
associated with the Printer object itself (as compared to the entry in
the directory which only represents the Printer object).  This more
dynamic information includes state, currently loaded and ready media,
number of jobs at the Printer, errors, warnings, and so forth.

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

                        Expires June 19, July 16, 1998

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 the 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.
End users may also cancel the print job by using the Job object's
Cancel-Job operation.  The notification service(s) are out of scope
for IPP/1.0, 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/1.0 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
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:

  - "MANDATORY": each object SHALL support the attribute.
  - "OPTIONAL": each object OPTIONALLY supports the attribute.

There is no such similar labeling of attribute values.  However, if an
implementation supports an attribute, it MUST support at least one of
the possible values for that attribute.

                        Expires June 19, July 16, 1998

2.1 Printer Object

A major component of the IPP/1.0 model is the Printer object.  A
Printer object implements the IPP/1.0 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.

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 might or might not be capable
       of spooling jobs
     3b) The associated output devices might or might 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 configuration 3.

                        Expires June 19, July 16, 1998

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

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 can contain one or
more documents.  The information required to create a Job object is

                        Expires June 19, July 16, 1998

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 are OPTIONALLY
     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)
  - "job-description" attributes: These attributes describe the Job
     object's identification, state, size, etc. Except for "job-name",
     the The client does not supply values for supplies
     some of these attributes, they are
     set by and the Printer object. object generates
     others. (See section 4.3)

A Job object contains at least one document, but may contain multiple
documents.  A document consists of 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/1.0, 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 MUST be maintained persistently
along with the persistent storage of the object attributes.

A Printer object MAY represent one or more output devices.  A Printer
object MAY represent a logical device which "processes" jobs but never
actually uses a physical output device to put marks on paper (for
example a Web page publisher or an interface 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 new

                        Expires July 16, 1998

Job object would be created which would be almost identical to the

                        Expires June 19, 1998
existing Job object, however it would have new (different) Job object
identifiers (see section 2.4).

A Job object 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 copies of the stream in
other documents in the same or different Job objects.  If the
contained document is a reference to a stream of document data, other
documents (in the same or different Job object(s)) may reference the
same stream.

2.4 Object Identity

All Printer and Job objects are identified by an identifier so that
they can be persistently and unambiguously referenced.  The IPP/1.0
model requires that these identifiers be Uniform Resource Identifiers
(URIs) [RFC1630].  Often, the URI is a URL [RFC1738] [RFC1808].

IPP/1.0 does

An administrators configure Printer objects to either support or not specify how the URI
support authentication and/or message privacy using TLS [TLS] and
other security mechanisms via a single communication channel that has
some sort of negotiation mechanism or multiple communication channels,
one for each type of security configuration.  The mechanism for such
configuration is obtained, but outside the scope of IPP/1.0.  Section 8 provides a
full description of all security considerations.  However, it is
RECOMMENDED must be
mentioned here that if a Printer object is registered in a directory service
which end users and programs can interrogate.  Section 16 defines a
generic schema 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:

  - A single URI for the Printer object entries in the directory service.

Allowing Job over which clients and
     Printer objects negotiate to have determine a mutually agreeable
     security mechanism (if any), or
  - Multiple URIs allows for flexibility and
scalability.  In some implementations, the Printer object might create
Jobs that are processed in where each URI represents
     each of the same local environment as communication channels to the Printer object itself.  In (each
     with possibly different security characteristics and
     configurations).

To support this case, flexibility, the Job URI might just be IPP Printer object type defines a composition
of
multi-valued identification attribute called the Printer's "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 and some unique component for which identifies it, but it may have more than one URI
where each URI identifies a different communication channel to the Job object,
such
Printer.  The "printer-uri-supported" attribute has a companion

                        Expires July 16, 1998

attribute, the "uri-security-supported" attribute, that has the same
cardinality as "printer-uri-supported".  The purpose of the unique 32-bit positive integer mentioned later "uri-
security-supported" attribute is to indicate the security mechanisms
(if any) used for each URI listed in this
paragraph.  In other implementations, "printer-uri-supported".  These
two attributes are fully described in sections 4.4.1 and 4.4.2.

When a job is submitted to the Printer object might be via a
central clearing-house for validating all Job object creation
requests, and create request,
the Job client MUST supply only a single Printer object itself might URI.  The client
supplied Printer object URI MUST be created one of the values in some
environment that is remote from the "printer-
uri-supported" Printer object.  In this case, attribute.

Note:  IPP/1.0 does not specify how the
Job object's URI may have no relationship at all to client obtains the Printer
object's URI. However, many existing printing systems have local
models or interface constraints client
supplied URI, but it is RECOMMENDED that force Job objects to a Printer object be
identified using only
registered as an entry in a 32-bit positive integer rather than directory service.  End-users and programs
can then interrogate the directory searching for Printers. Section 16
defines a URI.
This numeric Job ID is only unique within generic schema for Printer object entries in the context of 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 to which includes the create request was originally submitted.  In order
to allow both types possibly many URIs for that Printer object
values of one its attributes.

When a client access submits a create request to Jobs (either by Job URI or by
numeric Job ID), when the Printer object, the
Printer object successfully processes a
create validates the request and creates a new Job, the Job object.
The Printer object SHALL
generate both a assigns the new Job URI and object a Job ID for URI which is stored in
the new "job-uri" Job object. attribute.  This
requirement allows all URI is then used by clients to access Printer objects and Job
objects no matter the local constraints imposed on as the client
implementation.

                        Expires June 19, 1998

In addition to a unique identifier, Printer objects and
target for subsequent Job objects
have names.  An object name need not be unique across all instances of
all objects. A operations.  The Printer object's name is chosen and set by an
administrator through some mechanism outside the scope of IPP/1.0.  A object generates a
Job object's name is optionally chosen URI based on its configured security policy and supplied the URI used by
the IPP client
submitting in the job.  If create request (if there is more than one URI for
the client does not supply Printer object).

  For example, consider a Job object name,
the Printer object generates that supports both a name for the new Job object.  In all
cases,
  communication channel secured by the name only has local meaning; the name use of SSL3 (using an "https"
  schemed URI) and another open communication channel that is not constrained to
be unique.

To summarize:

  - Each Printer object is uniquely identified
  secured with SSL3 (using an simple "http" schemed URI).  If a URI.  The
     Printer's "printer-uri" attribute contains
  client were to submit a job using the URI.
  - Each Job secure URI, the Printer
  object is uniquely identified with a URI.  The Job's
     "job-uri" attribute contains would assign the URI.
  - Each new Job object is also uniquely identified with a combination of
     the secure URI of the Printer object as well.  If a
  client were to which the create request was
     originally submitted along with submit a Job ID (a 32-bit, positive
     integer) that is unique within job using the context of that Printer
     object.  The Printer object's "printer-uri" contains open-channel URI, the Printer
     URI.  The Job object's "job-id" attribute contains
  would assign the numeric new Job ID.
  - Each object an open-channel URI.

In addition, the Printer object has a name (which also fills in the Job object's "job-
printer-uri" attribute.  This is not necessarily unique).
     The administrator chooses and sets this name through some
     mechanism outside a reference back to the scope of IPP/1.0 itself.  The Printer
     object's "printer-name" attribute contains
object that created the name.
  - Each Job object object.  If a client only has access to a name (which is not necessarily unique).
     The
Job object's "job-uri" identifier, the client optionally supplies this name can query the "job-
printer-uri" attribute in order to determine which Printer object
created the create request. Job object.  If the client does not supply this name, Printer object supports more than one
URI, the Printer object
     generates a name for picks the Job object. The Job object's "job-name"
     attribute contains one URI supplied by 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, when
creating the
client issues an operation request job to populate the URI for that object.
Operations "job-printer-uri" attribute.

                        Expires July 16, 1998

Allowing Job objects to have attributes that supply information about URIs allows for flexibility and
scalability.  For example, in some implementations, the operation
itself.  These attributes are called operation attributes (as compared
to Printer object attributes such
might create Jobs that are processed in the same local environment as
the Printer object attributes or itself.  In this case, the Job object
attributes).  Each request carries along with it any operation
attributes, object attributes, and/or document data required URI might just be a
composition of the Printer's URI (the URI used by the submitting
client if the Printer object to perform supports more than one URI) and some
unique component for the operation.  Each request requires a response
from Job object, such as the object.  Each response indicates success or failure of unique 32-bit
positive integer mentioned later in this paragraph.  In other
implementations, the
operation with Printer object might be a status code.  The response contains any operation

                        Expires June 19, 1998

attributes, central clearing-house
for validating all Job object attributes, and/or status messages generated by creation requests, and the
execution of Job object
itself might be created in some environment that is remote from the operation request.

This section describes
Printer object.  In this case, the semantics of Job object's URI may have no
physical-location relationship at all to the IPP operations, both
requests Printer object's URI.
Again, this allows for flexibility and responses, in 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 a 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 SHALL 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.  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 IPP/1.0.  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; the name is not constrained to be unique.

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 various Printer object URIs
     (e.g., 'tls' or 'none').
  - Each Job object is identified with a Job URI.  The Job's "job-
     uri" attribute contains the URI.

                        Expires July 16, 1998
  - 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 (using one of its URIs) which created the Job object.
  - Each Job object has a "job-printer-uri" attribute which contains
     the URI of the Printer object that was used when creating 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 for operations 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 IPP/1.0 itself.  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.
Operations have attributes that supply information about the operation
itself.  These 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 by the
object 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.  The response contains any operation
attributes, object attributes, and/or status messages generated by the
execution of the operation request.

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

The IPP/1.0 Printer operations are:

  Print-Job (section 3.2.1)
  Print-URI (section 3.2.2)
  Validate-Job (section 3.2.3)

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  Create-Job (section 3.2.4)
  Get-Printer-Attributes (section 3.2.5)
  Get-Jobs (section 3.2.6)

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)

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

3.1 Common Semantics

The following sections describe the common elements and features of
all IPP operations. Operations are always used in request/response
pairs.

3.1.1 Operation Characteristics IDs and Request IDs

Each type of IPP operation type is identified defined as one of the values of the
"operations-supported" Printer attribute (see section 4.4.13).  The
client specifies the operation by including an operation code (section
4.4.13).  Operations are always used "operation-id"
attribute.  .  The "operation-id" is passed in request/response pairs. every request and each
corresponding response.  Each operation request also carries with it a request ID.
"request-id" attribute. This request id "request-id" attribute allows clients to
manage multiple outstanding requests.  For each operation request, the
client chooses an integer (possibly unique depending on client
requirements) in the range from 0 1 to 2**31 - 1 (inclusive).  The
receiving IPP object, copies the client supplied
request id "request-id"
attribute into the response so that the client can match up the
correct response with the right outstanding request.  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 which case sent.  In such cases, the request id "request-id" attribute would
not be essential for correct

                        Expires June 19, 1998 protocol operation).  However, operation,  however, in other
mappings, the operation responses can come back in any order (in which case order.  In
these cases, the request id "request-id" would be essential). essential.

                        Expires July 16, 1998

3.1.2 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 MANDATORY and which are OPTIONAL
     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 section 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 are unsupported by the Printer object,
     the Printer object returns the set of unsupported attributes in
     the response.  Section 15 gives 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 for
     any reason unknown) attributes or values that it does not
     support.  In such cases for any operation

                        Expires June 19, 1998 request (not just
     create requests), the IPP object MUST return these  unsupported
     attributes.

                        Expires July 16, 1998

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. order, unless specified otherwise.

Each attribute specification includes the attribute's name followed by
the name of its attribute syntax(es) in parenthesizes.  In addition,
the 'integer' attributes are followed by the allowed range in
parenthesizes, (m:n), for the integer value.  The 'text' and 'name'
attributes are followed by the (size) in octets in parenthesizes.  For
more details on attribute syntax notation, see the descriptions of
these attributes syntaxes in section 4.1.  It is an operation error
for clients to supply in operation requests and/or IPP objects to
returns in operations responses attribute value(s) that do not match
the syntax(es) defined for that attribute (see section 3 for operation
attributes and section 4 for IPP object attributes).

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.

Note: Some operations are MANDATORY 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 MANDATORY 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).  It is non-conformance when an  An IPP object is non-conformant if it does not
support a MANDATORY operation.

3.1.2

3.1.3 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 (the as the
target of the operation.  The client identifies the target object by
supplying the correct URI in the "printer-uri" attribute). operation attribute.

                        Expires July 16, 1998

For Job operations, the operation is directed at either:

                        Expires June 19, 1998

  - the The Job object itself using the Job object's URI (the "job-uri"
     attribute assigned URI.  In this case,
     the client identifies the target object by supplying the Printer object), or
  - correct
     URI in the "job-uri" operation attribute.
  - The Printer object to which that created the job was originally submitted Job object using both the
     Printer objects URI of and the Job object's Job ID.  Since the
     Printer ("printer-uri") in combination with object that created the 32-bit numeric Job object generated the Job ID,
     it MUST be able to correctly associate the client supplied Job ID (the "job-id"
     with the correct Job object.  The client supplies the Printer
     object's URI in the "printer-uri" operation attribute assigned by and the Job
     object's Job ID in the
     Printer object). "job-id" operation attribute.

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

The operation target is a MANDATORY operation attribute that MUST be
included in every operation request.

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

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

  2. If the protocol scheme for the URI does not allow an explicit
     port number specification, then the default port number for the
     protocol MUST be used.

3.1.3

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 MANDATORY
operation attributes for every IPP request and response.  These
attributes are "attributes-charset" and "attributes-natural-language"
which SHALL be stored 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.

3.1.3.1

                        Expires July 16, 1998

3.1.4.1 Request Operation Attributes

The client SHALL supply and the Printer object SHALL support the
following MANDATORY operation attributes in every IPP/1.0 operation
request:

                        Expires June 19, 1998

  "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 SHALL 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 specification of the 'text' and
     'name' attribute syntaxes.

     All IPP objects SHALL support the 'utf-8' charset [RFC2044] 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 SHALL reject
     the request and return the 'client-error-charset-not-supported'
     status code.  The Printer object SHALL indicate the charset(s)
     supported as the values of the "charset-supported" Printer
     attribute (see Section 4.4.15), so that the client MAY query
     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 or ISO-8859-
     1.  Then the client will have to filter 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 4.1.9
     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

                        Expires July 16, 1998
     'name' attributes and status messages that the Printer object
     returns in the response to this request.

     There are no MANDATORY natural languages required for the Printer
     object to support.  However, the Printer object's "generated-
     natural-language-supported" attribute SHALL identify the natural

                        Expires June 19, 1998
     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 3.1.4), 3.1.5), the Printer object SHALL
     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 SHALL return these
     generated messages in the Printer's configured natural language
     as specified by the Printer's "natural-language-configured"
     attribute" (see Section 4.4.16).

     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
     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", the client SHALL use the Natural
     Language Override mechanism (see sections 4.1.2 and 4.1.4) for
     each such attribute value supplied.

     The IPP object SHALL 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 SHALL remember that natural
     language for all client supplied attributes, and  when returning

                        Expires July 16, 1998
     those attributes in response to a query, the IPP object SHALL
     indicate that natural language.

     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-
     natural-language" attribute, or if different, as identified by

                        Expires June 19, 1998
     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.  An IPP object SHALL 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 . Override.

     See the 'naturalLanguage' attribute syntax description in Section section
     4.1.10 for the syntax and semantic interpretation of the values
     of this attribute and for example values.

Clients SHOULD NOT request 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 it also supports
natural languages 'en' (English), 'fr' (French), and 'el' (Greek).  If
the client requests 'iso-8859-1' and 'el', it is an invalid
combination of charset and natural language.  In this case, the IPP
object SHALL NOT change either of these attribute values and SHALL
accept them as if they were valid.

3.1.3.2

3.1.4.2 Response Operation Attributes

The Printer object SHALL supply and the client SHALL support the
following MANDATORY operation attributes in every IPP/1.0 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 SHALL 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 SHALL be
     rejected.  See "attributes-charset" described in Section 3.1.3.1 3.1.4.1
     above.

                        Expires July 16, 1998
     If the Printer object supports more than just the 'utf-8'
     charset, the Printer object SHALL 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

                        Expires June 19, 1998
     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.

     Note: 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 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
     SHALL use the Natural Language Override mechanism (see sections
     4.1.2 and 4.1.4) on each attribute value returned.

3.1.4

3.1.5 Operation Status Codes and Messages

Every operation response returns a MANDATORY status code "status-code" operation
attribute and an OPTIONAL status message represented as the "status-message" text(255) operation attribute.  A status code The
"status-code" attribute provides information on the processing of a
request.  A "status-message" attribute provides a short textual
description of the status of the operation.  The status code is
intended for use by automata, and the status message is intended for
the human end user.  If a response does include a "status-message"

                        Expires July 16, 1998

attribute, an IPP client NEED NOT examine or display the status message,
however it SHOULD do so in some implementation specific manner.

The status code value of a "status-code" attribute is a numeric value that has
semantic meaning.   The
Model specification does not give the status code a name, so it is not
like other attributes; it is only a numeric code by itself.  The

                        Expires June 19, 1998

status code "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.  The "status-message" attribute's syntax
is text(255).

A client implementation of IPP SHOULD convert status code values into
any localized message that has semantic meaning to the end user.  If
the Printer object supports the status message, 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 3.1.3.1). section 3.1.4.1).  As described in Section
3.1.3.1 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.

3.1.5

3.1.6 Versions

Each operation request and response carries with it a version number. "version-number"
attribute.  Each version number value of the "version-number" attribute 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 (the requester) to identify which version of IPP
it is interested in using.  If the IPP object does not support that
version, the object responds with a status code of 'server-error-version-not-supported'. 'server-error-
version-not-supported'.

There is no version negotiation per se.  However, if after receiving a
'server-error-version-not-supported' status code from an IPP object,
there is nothing that prevents a client from trying again with a
different version number. In order to conform to IPP/1.0, an
implementation MUST support at least version '1.0'.

There is only one notion of version that covers both IPP Model and IPP
Protocol changes. Thus the version number MUST change when introducing
a new version of the Model document or a new version of the Protocol
document.

                        Expires July 16, 1998

Changes to the major version number indicate structural or syntactic
changes that make it impossible for older version of IPP clients and
Printer objects to correctly parse and 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 "ipp-attribute-fidelity" attribute (if it had not been part

                        Expires June 19, 1998
of version '1.0'), would have required a change to the major version
number.  Items that might affect the changing of the major version
number include any changes to the protocol specification itself, such
as:

  - reordering of ordered attributes or attribute sets
  - changes to the syntax of existing attributes
  - changing Operation or Job Template attributes from OPTIONAL to
     MANDATORY and vice versa
  - adding MANDATORY (for an IPP object to support) operation
     attributes
  - adding MANDATORY (for an IPP object to support) operation
     attribute groups
  - adding values to existing operation attributes
  - adding MANDATORY 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 protocol
specification itself (except adding attribute syntaxes), such as:

  - 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 MANDATORY or vice versa.

The encoding of the operation code, "operation-id", the version number, "version-number", and the
request id
"request-id" SHALL NOT change over any version number (either major or
minor).  This rule guarantees that all future versions will be
backwards compatible with all previous versions (at least for checking

                        Expires July 16, 1998

the operation code, "operation-id", the version number, "version-number", and the request id). "request-id").  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.

                        Expires June 19, 1998

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

3.1.6

3.1.7 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 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 specification, the term "create request" is used
to refer to any of these three operation requests.

                        Expires July 16, 1998

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 MANDATORY operation
(all implementations MUST support it) whereas Create-Job is an
OPTIONAL operation, hence some implementations might not support it.

                        Expires June 19, 1998

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' or
'pending-held' state.  Later, the Printer object begins processing the
print job.  At this point in time, 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

Section 15 describes the rules and issues surrounding the processing
of client supplied attributes. Section 15.3 presents suggested steps
for an IPP object to either accept or reject any request.  Section
15.4 presents suggested additional steps for processing create
requests.

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

  1. Validate the document data
  2. Validate 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 yet be done again at job processing time.
Also, in the case of a URI, checking for availability at job
submission time does not guarantee availability 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,

                        Expires July 16, 1998
  - 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 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

                        Expires June 19, 1998
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-
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
IPP/1.0.

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 MANDATORY 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 a 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

  Target:
     The "printer-uri" operation attribute which is the target for
     this operation as described in section 3.1.2. 3.1.3.

  Natural Language and Character Set:
     The "attributes-charset" and "attributes-natural-language"
     attributes as described in section 3.1.3.1. 3.1.4.1.  The Printer object

                        Expires July 16, 1998
     SHALL copy these values to the corresponding Job Description
     attributes described in sections 4.3.24 4.3.23 and 4.3.25. 4.3.24.

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

                        Expires June 19, 1998

  "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 4.3.4). 4.3.5).

  "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 SHALL reject the
     Print-Job request.  The value 'false' indicates that a reasonable
     attempt to print the Job object is acceptable and the Printer
     object SHALL 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"
     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/1.0 does not support
     the concept of document level attributes.

                        Expires July 16, 1998
  "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.  If the
     client does not supply this attribute, the Printer object assumes
     that the document data is in the format defined by the Printer

                        Expires June 19, 1998
     object's "document-format-default" attribute.  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 SHALL reject the request and return the 'client-
     error-document-format-not-supported' status code.

  "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.

  "compression" (type3 keyword)
     The client OPTIONALLY supplies this attribute.  The Printer
     object OPTIONALLY supports this attribute.  It the "compression-supported" attribute
     (see section 4.4.29).  The client supplied "compression"
     operation attribute identifies the compression algorithm used on
     the document data (see section
     4.3.17). data.  If the client omits this attribute, the
     Printer object SHALL assume that the data is not compressed.  If
     the client supplies the attribute and the Printer object supports
     the attribute, the value of Printer object uses the attribute is used to populate corresponding
     decompression algorithm on the Job
     object's "compression" Job Description attribute. document data. 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 SHALL 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.

  "job-k-octets" (integer(0:MAX))
     The client OPTIONALLY supplies this attribute.  The Printer
     object OPTIONALLY supports this attribute.  It the "job-k-octets-supported" attribute
     (see section 4.4.30).  The client supplied "job-k-octets"
     operation attribute identifies the total size of the document(s)
     in K octets being submitted (see section 4.3.18 4.3.17 for the complete
     semantics).  If the client supplies the attribute and the Printer
     object supports the attribute, the value of the attribute is used

                        Expires July 16, 1998
     to populate the Job object's "job-k-octets" Job Description
     attribute.

     Note:  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, but and the value is outside within the range of the corresponding
     Printer object's "xxx-supported" attribute, the Printer object
     SHALL use the value to populate the Job object's

                        Expires June 19, 1998 "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 SHALL 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' 'client-error-attributes-or-values-not-supported'
     status code.  If the client does not supply the attribute, the
     Printer object might 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.

  "job-impressions" (integer(0:MAX))
     The client OPTIONALLY supplies this attribute.  The Printer
     object OPTIONALLY supports this attribute.  It the "job-impressions-supported"
     attribute (see section 4.4.31).  The client supplied "job-
     impressions" operation attribute identifies the total size in
     number of impressions of the document(s) being submitted (see
     section 4.3.19 4.3.18 for the complete semantics).

     See note under "job-k-octets".

  "job-media-sheets" (integer(0:MAX))
     The client OPTIONALLY supplies this attribute.  The Printer
     object OPTIONALLY supports this attribute.  It the "job-media-sheets-supported"
     attribute (see section 4.4.32).  The client supplied "job-media-
     sheets" operation attribute identifies the total number of media
     sheets to be produced for this job (see section 4.3.20 4.3.19 for the
     complete semantics).

     See note 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.

                        Expires July 16, 1998

Group 3: Document Content

     The client MUST supply the document data to be processed.

Note: The simplest Print-Job Request consists of just the Document
Content, the "attributes-charset" and "attributes-natural-language"
operation attributes, and nothing else.  In this 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 3.1.3.1) 3.1.4.1) (if
     those are supported, otherwise using the Printer object's default
     natural language and charset), and

                        Expires June 19, 1998
  - 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 SHALL return to the client the following sets of
attributes as part of the Print-Job Response:

Group 1: Operation Attributes

  Status Code and Message:
     The response includes the MANDATORY status code and an OPTIONAL
     "status-message" (text) operation attribute as described in
     section 3.1.4. 3.1.5.  If the client supplies unsupported or conflicting
     Job Template attributes or values, the Printer object SHALL
     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 section 15 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 3.1.3.2. 3.1.4.2.

Group 2: Unsupported Attributes

     This is a set of Operation and Job Template attributes supplied
     by the client (in the request) that are not supported by the

                        Expires July 16, 1998
     Printer object or that conflict with one another (see sections
     15.3 and 15.4).

     Unsupported attributes fall into three categories:

     1. The Printer object does not support the named attribute (no
          matter what the value).
     2. The Printer object does support the attribute, but does not
          support some or all of the particular values supplied by the
          client (i.e., the Printer object does not have those values
          in the corresponding supported values 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.

                        Expires June 19, 1998

     In the case of an unsupported attribute name, the Printer object
     returns the client-supplied attribute with a substituted special "out-of-
     band" value of 'unsupported' indicating no support for the
     attribute
     itself. itself (see the beginning of section 4.1).

     In the case of a supported attribute with one or more unsupported
     values, the Printer object simply returns the client-supplied
     attribute with the unsupported values as supplied by the client.
     This indicates support for the attribute, but no support for that
     particular 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
     values, the Printer object SHALL return only those values that
     are unsupported.

     In the case of two (or more) supported attribute values that are
     in conflict with one another because they cannot be used together
     in the same job, the Printer object SHALL return all the values
     that it ignores or substitutes to resolve the conflict, but not
     any of the values that it is still using.  The choice for exactly
     how to resolve the conflict is implementation dependent.  See
     Section 15.4.3 15.4.4 for an example.

     In these three cases, the value of the "ipp-attribute-fidelity"
     supplied by the client does not affect what the Printer object
     returns.  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.

                        Expires July 16, 1998

Group 3: Job Object Attributes

  "job-uri" (uri):
     The Printer object MUST return the Job object's URI by returning
     the contents of the MANDATORY  "job-
     uri" "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 is 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":
     The Printer object MUST return the Job object's Job ID by
     returning the MANDATORY  "job-
     id"  "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":
     The Printer object MUST return the Job object's MANDATORY "job-
     state" attribute. The value of this attribute (along with the
     value of the next attribute "job-state-reasons") is taken from a

                        Expires June 19, 1998
     "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":
     The Printer object OPTIONALLY returns the Job object's OPTIONAL
     "job-state-reasons" 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-reasons" attribute is not supported and will
     not be returned in a subsequent Job object query.

  "job-state-message":
     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.

                        Expires July 16, 1998
  "number-of-intervening-jobs":
     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 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: The simplest response consists of the just the MANDATORY Job
Object Attributes, the MANDATORY "attributes-charset" and "attributes-
natural-language" operation attributes, and a status code of
"successful-ok".

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
rather than including the document data itself.  Before returning the
response, the Printer MUST validate that the Printer supports the

                        Expires June 19, 1998
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 SHALL reject the
request and return the 'client-error-uri-scheme-not-supported' status
code.  See Section 15.3.4 15.3.5 for suggested additional checks.  The
Printer NEED NOT follow the reference and validate the contents of the
reference.

If the Printer object supports this operation, it MUST support the
"reference-uri-schemes-supported" Printer attribute (see section
4.4.24).

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 MANDATORY operation is similar to the Print-Job operation
(section 3.2.1) except that a client supplies no document data and the

                        Expires July 16, 1998

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 check that the same Print-Job operation will be accepted
without having to send the document data.  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.

Note: 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

                        Expires June 19, 1998
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-name", "document-format", and
"document-natural-language" attributes for each document in the multi-document multi-
document Job object.  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.

3.2.5 Get-Printer-Attributes Operation

This MANDATORY operation allows a client to request the values of the
attributes of a Printer or Job object.  This section describes the
former and section 3.3.4 describes the latter.   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.

                        Expires July 16, 1998

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

  - 'job-template': all of the Job Template attributes that apply to
     a Printer object (the last two columns of the table in Section
     4.2).
  - 'printer-description': the attributes specified in Section 4.4.
  - 'all': the special group 'all' that includes all supported
     attributes.

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 MANDATORY 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 when the request is directed to a Printer object:

                        Expires June 19, 1998

Group 1: Operation Attributes

  Target:
     The "printer-uri" operation attribute which is the target for
     this operation as described in section 3.1.2. 3.1.3.

  Natural Language and Character Set:
     The "attributes-charset" and "attributes-natural-language"
     attributes as described in section 3.1.3.1. 3.1.4.1.

  Requesting User Name:
     The "requesting-user-name" 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 SHALL respond as if
     this attribute had been supplied with a value of 'all'.

                        Expires July 16, 1998
  "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 SHALL return the attributes and values that 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'.

     If the Printer object does not distinguish between different
     document formats when validating jobs in the create and Validate-
     Job operations, it SHALL NOT distinguish between document formats
     in the Get-Printer-Attributes operation.  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.

                        Expires June 19, 1998

     If the client omits this attribute, the Printer object SHALL
     respond as if the attribute had been supplied with a value equal
     to the value of the Printer object's "document-format-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 4.1.11.

     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 SHALL reject the
     operation and return the 'client-error-document-format-not-
     supported' status code.

                        Expires July 16, 1998

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 Code and Message:
     The response includes the MANDATORY status code and an OPTIONAL
     "status-message" (text) operation attribute as described in
     section 3.1.4. 3.1.5.

  Natural Language and Character Set:
     The "attributes-charset" and "attributes-natural-language"
     attributes as described in section 3.1.3.2. 3.1.4.2.

Group 2: Unsupported Attributes

     This is a set of Operation attributes supplied by the client (in
     the request) that are not supported by the Printer object or that
     conflict with one another (see sections 3.2.1.2 and 15).

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
     SHALL respond with the 'unknown' value for any supported

                        Expires June 19, 1998
     attribute (including all MANDATORY attributes) for which the
     Printer object does not know the value.  Also the Printer object
     SHALL respond with the 'no-value' for any supported attribute
     (including all MANDATORY attributes) for which the system
     administrator has not configured a value.  See the description of
     the 'out-of-band' "out-of-band" values in the beginning of Section 4.1.

3.2.6 Get-Jobs Operation

This MANDATORY 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 for a Job object, operation, except
that this Get-Jobs operation returns attributes from possibly more

                        Expires July 16, 1998

than one object (see the description of Job attribute group names in
section 3.3.4).

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

  Target:
     The "printer-uri" operation attribute which is the target for
     this operation as described in section 3.1.2. 3.1.3.

  Natural Language and Character Set:
     The "attributes-charset" and "attributes-natural-language"
     attributes as described in section 3.1.3.1. 3.1.4.1.

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

  "limit" (integer(1:MAX)):
     The client OPTIONALLY supplies this attribute.  The Printer
     object MUST support this attribute. It is an integer value that
     indicates a limit to the number of Job objects 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

                        Expires June 19, 1998
     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 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 SHALL respond as if the client had supplied this
     attribute with two values: 'job-uri' and 'job-id'.

                        Expires July 16, 1998
  "which-jobs" (keyword):
     The client OPTIONALLY supplies this attribute.  The Printer
     object MUST support this attribute.  It indicates which Job
     objects SHALL 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', 'unknown'.
          held'.

     A Printer object SHALL 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 SHALL
     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.

     If the client does not supply this attribute, the Printer object
     SHALL 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 all
     jobs or just the jobs submitted by the requesting user of this
     request  SHALL be returned by the Printer object.  If the client
     does not supply this attribute, the Printer object SHALL respond

                        Expires June 19, 1998
     as if the client had supplied the attribute with a value of
     'false', i.e., all jobs.  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 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.

Group 1: Operation Attributes

                        Expires July 16, 1998
  Status Code and Message:
     The response includes the MANDATORY status code and an OPTIONAL
     "status-message" (text) operation attribute as described in
     section 3.1.4. 3.1.5.

  Natural Language and Character Set:
     The "attributes-charset" and "attributes-natural-language"
     attributes as described in section 3.1.3.2. 3.1.4.2.

Group 2: Unsupported Attributes

     This is a set of Operation attributes supplied by the client (in
     the request) that are not supported by the Printer object or that
     conflict with one another (see sections 3.2.1.2 and 15.3).

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 SHALL respond with the 'unknown' value for any
     supported attribute (including all MANDATORY 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' "out-of-
     band" values in the beginning of Section 4.1.

     For any job submitted in a different natural language than the
     natural language that the Printer object is returning in the
     "attributes-natural-language" operation attribute in the Get-Jobs

                        Expires June 19, 1998
     response, the Printer SHALL indicate the submitted natural
     language by returning the Job object's "attributes-natural-
     language" as the first Job object attribute, which overrides the
     "attributes-natural-language" operation attribute value being
     returned by the Printer object.  If any returned 'text' or 'name'
     attribute includes a Natural Language Override as described in
     the sections 4.1.2 and 4.1.4, the Natural Language Override
     overrides the Job object's "attributes-natural-language" value
     and/or the "attributes-natural-language" operation attribute
     value.

     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

                        Expires July 16, 1998
          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', 'processing-
          stopped', and 'unknown' '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).

3.3 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.

Since the Create-Job and the send operations (Send-Document or Send-
URI operations) that follow can occur over arbitrarily long periods of
time, each Printer object must decide how long to "wait" for the next

                        Expires June 19, 1998
send operation.  The Printer object OPTIONALLY supports the "multiple-
operation-timeout" attribute.  This attribute indicates the maximum
number of seconds the Printer object will wait for the next send
operation.  If the Printer object times-out waiting for the next send
operation, the Printer object MAY decide on any of the following
semantic actions:

  1. Assume that the Job is an invalid job, start the process of
     changing the job state to 'aborted', 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 it 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

                        Expires July 16, 1998
     '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'
     to allow an operator to determine whether or not to continue
     processing the Job by moving it back to the 'pending' state.

Each implementation is free to decide the "best" action to take
depending on local policy, the value of "ipp-attribute-fidelity",
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.

3.3.1.1 Send-Document Request

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

Group 1: Operation Attributes

  Target:
     Either (1) the "printer-uri" plus "job-id" or (2) the "job-uri"
     operation attribute(s) which define the target for this operation
     as described in section 3.1.2. 3.1.3.

  Natural Language and Character Set:
     The "attributes-charset" and "attributes-natural-language"
     attributes as described in section 3.1.3.1. 3.1.4.1.

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

                        Expires June 19, 1998

  "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.

                        Expires July 16, 1998
  "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.  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.  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 SHALL reject the request and return the 'client-
     error-document-format-not-supported' status code.

  "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. unambiguously.  There are
     no particular values required for the Printer object to support.

  "compression" (type3 keyword)
     The client OPTIONALLY supplies this attribute.  The Printer
     object OPTIONALLY supports the "compression-supported" attribute
     (see section 4.4.29).  The client supplied "compression"
     operation attribute identifies the compression algorithm used on
     the document data.  If the client omits this attribute, the
     Printer object SHALL assume that the data is not compressed.  If
     the client supplies the attribute and the Printer object supports
     the attribute, the Printer object SHALL use the corresponding
     decompression algorithm on the document data. 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 SHALL 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.

  "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

                        Expires July 16, 1998
     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 Send-
     Document request with no document data where the "last-document"
     flag is set to 'true'.  Such a request SHALL NOT increment the
     value of the Job object's

                        Expires June 19, 1998 "number-of-documents" attribute, since
     no real document was added to the job.

3.3.1.2 Send-Document Response

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

Group 1: Operation Attributes

  Status Code and Message:
     The response includes the MANDATORY status code and an OPTIONAL
     "status-message" (text) operation attribute as described in
     section 3.1.4. 3.1.5.

  Natural Language and Character Set:
     The "attributes-charset" and "attributes-natural-language"
     attributes as described in section 3.1.3.2. 3.1.4.2.

Group 2: Unsupported Attributes

     This is a set of Operation attributes supplied by the client (in
     the request) that are not supported by the Printer object or that
     conflict with one another (see sections 3.2.1.2 and 15.3).

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).

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

                        Expires July 16, 1998

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.

                        Expires June 19, 1998

3.3.3 Cancel Job Operation

This MANDATORY operation allows a client to cancel a Print Job any
time after a create job operation.  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.

3.3.3.1 Cancel-Job Request

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

Group 1: Operation Attributes

  Target:
     Either (1) the "printer-uri" plus "job-id" or (2) the "job-uri"
     operation attribute(s) which define the target for this operation
     as described in section 3.1.2. 3.1.3.

  Natural Language and Character Set:
     The "attributes-charset" and "attributes-natural-language"
     attributes as described in section 3.1.3.1. 3.1.4.1.

  Requesting User Name:
     The "requesting-user-name" 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).

                        Expires July 16, 1998

3.3.3.2 Cancel-Job Response

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

Group 1: Operation Attributes

  Status Code and Message:
     The response includes the MANDATORY status code and an OPTIONAL
     "status-message" (text) operation attribute as described in
     section 3.1.4.

                        Expires June 19, 1998 3.1.5.

     If the job is already in the 'completed', 'aborted', or
     'canceled' state, or the 'process-to-stop-point' value is set in
     the Job's "job-state-reasons" attribute, the Printer object SHALL
     reject the request and return the 'client-error-not-possible'
     error status code.

  Natural Language and Character Set:
     The "attributes-charset" and "attributes-natural-language"
     attributes as described in section 3.1.3.2. 3.1.4.2.

Group 2: Unsupported Attributes

     This is a set of Operation attributes supplied by the client (in
     the request) that are not supported by the Printer object or that
     conflict with one another (see sections 3.2.1.2 and 15.3).

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 4.3.6), 4.3.7), the
"job-state-reasons" attribute SHOULD contain the ' processing-to-stop-
point ' 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 MANDATORY 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.

                        Expires July 16, 1998

For Jobs, the possible names of attribute groups are:

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

                        Expires June 19, 1998

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
MANDATORY that each Job object support all 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:

Group 1: Operation Attributes

  Target:
     Either (1) the "printer-uri" plus "job-id" or (2) the "job-uri"
     operation attribute(s) which define the target for this operation
     as described in section 3.1.2. 3.1.3.

  Natural Language and Character Set:
     The "attributes-charset" and "attributes-natural-language"
     attributes as described in section 3.1.3.1. 3.1.4.1.

  Requesting User Name:
     The "requesting-user-name" 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

                        Expires July 16, 1998
     SHALL 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

                        Expires June 19, 1998

  Status Code and Message:
     The response includes the MANDATORY status code and an OPTIONAL
     "status-message" (text) operation attribute as described in
     section 3.1.4. 3.1.5.

  Natural Language and Character Set:
     The "attributes-charset" and "attributes-natural-language"
     attributes as described in section 3.1.3.2. 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

     This is a set of Operation attributes supplied by the client (in
     the request) that are not supported by the Printer object or that
     conflict with one another (see sections 3.2.1.2 and 15.3).

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 SHALL respond with
     the 'unknown' value for any supported attribute (including all
     MANDATORY 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' "out-of-band" values in the beginning of
     Section 4.1.

4. Object Attributes

This section describes the attributes with their corresponding
attribute syntaxes and values that are part of the IPP model.  The

                        Expires July 16, 1998

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 specifications:

  - 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.

                        Expires June 19, 1998
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 SHALL 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 SHALL
include the semantics of the attribute syntax(es) so identified.
Section 6 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, responses the value of an attribute in a response (but not requests) in a
request) MAY be one of the "out of band" "out-of-band" values.   Standard "out-of-band" "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 SHALL 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 system administrator has not yet configured a value.

                        Expires July 16, 1998

The protocol specification defines mechanisms for allowing passing
"out of "out-of-
band" values.  All attributes in a request SHALL have one or more
values as defined in Sections 4.2 to 4.4.  Thus clients SHALL not
supply attributes with "out-of-band" values.  All attribute in a
response SHALL 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 "|"

                        Expires June 19, 1998
character in the sub-section heading to indicate the choice.  Since
each value SHALL 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'

The 'text' attribute syntax is a sequence of one or more characters
encoded in a maximum of 1023 octets which is indicated in sub-section
headers using the notation: text(MAX).  If an attribute is specified
to have a smaller maximum in its sub-section header description, the
explicit number of octets is indicated.  For example: the "printer-
location" attribute is specified as:  printer-location (text(127)).

The Printer object SHALL support the UTF-8 charset [RFC2044] and MAY
support additional charsets to represent 'text' values, provided that they
the charsets are registered with IANA [IANA-CS] to represent 'text' values. [IANA-CS].  See Section 4.1.9
for the specification of the 'charset' attribute syntax, including
restricted semantics and examples of charsets.

In this specification, attributes that are indicated to have the
'text' attribute syntax, also automatically have the
'textWithLanguage' attribute syntax.  See section 4.1.2.

If the client needs to supply or the Printer object needs to return a
'text' attribute in a different natural language from the rest of the
'text' attributes in the request or response as indicated by the
"attributes-natural-language" operation attribute (see Section 3.1.3) 3.1.4)
or job attribute (see Section 4.3.25), 4.3.24), the client or Printer object
SHALL identify the natural language for that attribute.  This
MANDATORY mechanism for identifying the natural language of a single
attribute value is called the Natural Language Override mechanism.
This mechanism uses an alternate attribute syntax, called
'textWithLanguage', which is described in section 4.1.2.

                        Expires July 16, 1998

4.1.2 'textWithLanguage'

The 'textWithLanguage' attribute syntax is a compound attribute syntax
consisting of two parts: a 'text' part plus an additional
'naturalLanguage' (see section 4.1.10) 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.  The 'text' part is limited to 1023 octets, and the
'naturalLanguage' part is limited to 63 octets.  If the sub-section
header specifying an attribute with attribute syntax 'text' with a

                        Expires June 19, 1998
smaller explicit value than MAX, that value applies to the 'text' part
of the 'textWithLanguage' as well.

If the client needs to supply or the Printer object needs to return a
'text' attribute value in a different natural language from the rest
of the 'text' attribute values in the request or response as indicated
by the "attributes-natural-language" operation attribute (see Section
3.1.3)
3.1.4) or to the "attributes-natural-language" Job attribute, if
present, in the case of a Get-Jobs response ,the response, the client or IPP object
SHALL identify the natural language for that attribute using the
'textWithLanguage' attribute syntax.

The 'textWithLanguage' attribute syntax is the so-called Natural
Language Override mechanism for the 'text' attribute syntax and MUST
be supported by IPP objects.

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 or
to the "attributes-natural-language" Job attribute, if present, in the
case of a Get-Jobs response.

Any attribute that is specified to have the 'text' attribute syntax in
this document, automatically also has the 'textWithLanguage' attribute
syntax.  IPP objects SHALL accept, support, and return both the 'text'
and 'textWithLanguage' attribute syntaxes for any attribute in this
specification that is indicated to have the 'text' attribute syntax.
For brevity in this specification, only the 'text' attribute syntax is
indicated for attributes.  However, the interpretation of 'text' SHALL
be as if it were: 'text | textWithLanguage'.

In a create request, the Printer object MUST accept and store with the
Job object any natural languages 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

                        Expires July 16, 1998

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

                        Expires June 19, 1998
  'Rapport Mensuel': the job name in French

See the Protocol document [IPP-PRO] for a detailed example of the
'textWithLanguage' attribute syntax.

4.1.3 'name'

The 'name' attribute syntax is the same as 'text', including the
MANDATORY support of UTF-8 and the Natural Language Override
mechanism, except that the sequence of characters is limited so that
its encoded form is of length 1 to 255 octets which is indicated in
sub-section headers using the notation: name(MAX).  If an attribute is
specified to have a smaller maximum, the explicit number of octets is
indicated.  For example: the "printer-name" attribute is specified as:
printer-name (name(127)).  This syntax type is used for user-
friendly user-friendly
strings, such as a Printer name, that, for humans, are more meaningful
than identifiers.

In this specification, attributes that are indicated to have the
'name' attribute syntax, also automatically have the
'nameWithLanguage' attribute syntax.  See section 4.1.4.

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

4.1.4 'nameWithLanguage'

The 'nameWithLanguage' attribute syntax is the same as
'textWithLanguage', including the MANDATORY support of UTF-8, except
that the length of the 'name' part SHALL not exceed 255 octets.  This
attribute syntax is the so-called Natural Language Override mechanism
for the 'name' attribute syntax and MUST be supported by IPP objects.

Example:  If the client supplies the "attributes-natural-language"
operation attribute with the value:  'en' indicating English, but the

                        Expires July 16, 1998

"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

4.1.5 'keyword'

The 'keyword' attribute syntax is a sequence of characters, length: 1
to 255, containing only the US-ASCII [ASCII] encoded values for

                        Expires June 19, 1998
lowercase letters ("a" - "z"), digits ("0" - "9"), hyphen ("-"), dot
("."), and underscore ("_").  The first character MUST be a lowercase
letter.  Furthermore, keywords SHALL 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 SHALL NOT use the Natural Language Override mechanism, since
they SHALL 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 SHALL 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 describes how
the protocol can be extended with new keyword values.  Examples of
attribute name keywords:

  "job-name"
  "attributes-charset"

                        Expires July 16, 1998

4.1.6 'enum'

The 'enum' attribute syntax is an enumerated integer value that is in
the range from -2**31 (MIN) 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 specification are also used
for corresponding attributes in other standards [RFC1759].  This
syntax type is not used for attributes to which the system

                        Expires June 19, 1998
administrator may assign values.  Section 6 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
"out-of-band" value 'unknown'.  See the description of the "out-of-band" "out-of-
band" values at the beginning of Section 4.1.  Therefore, most attributes
of type 'enum' often start at '3'.

4.1.7 'uri'

The 'uri' attribute syntax is any valid Uniform Resource Identifier or
URI [RFC1630].  Most often, URIs are simply Uniform Resource Locators
or URLs [RFC1738] [RFC1808].  The maximum length of URIs used within
IPP is 1023 octets.

4.1.8 'uriScheme'

The 'uriScheme' attribute syntax is a sequence of characters
representing a URI scheme according to RFC 1738 [RFC1738].  Though RFC
1736 requires that the values be case-insensitive, IPP requires all
lower case to simplify comparing by IPP clients and Printer objects.
Standard values for this syntax type are the following keywords:

  'http':  for HTTP schemed URIs (e.g., "http://_") "http:_")
  'https':  for HTTPS schemed URIs (e.g., "https://...") "https:...")
  'ftp': for FTP schemed URIs (e.g., "ftp://...") "ftp:...")
  'mailto': for SMTP schemed URIs (e.g., "mailto:...")

                        Expires July 16, 1998
  '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 schemes used within IPP
is 63 octets.

4.1.9 'charset'

The 'charset' attribute syntax is a standard identifier for a charset.
A charset is a coded character set and encoding scheme.  Charsets are

                        Expires June 19, 1998
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
[IANA-CSa].  Though RFC 2046 requires that the values be case-
insensitive US-ASCII, IPP requires all lower case 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, SHALL be used.

The maximum length of charset values used within IPP is 63 octets.

Some examples are:

  'utf-8':  ISO 10646 Universal Multiple-Octet Coded Character Set
     (UCS) represented as the UTF-8 [RFC2044] transfer encoding scheme
     in which US-ASCII is a subset charset.  The 'utf-8' charset value
     supplied in the "attributes-charset" operation attribute (see
     Section 3.1.3), 3.1.4), which is used to identify the charset of 'text'
     and 'name' attributes, SHALL be restricted to any characters
     defined by ISO 10646 [ISO10646-1].
  'us-ascii':  7-bit American Standard Code for Information
     Interchange (ASCII), ANSI X3.4-1986 [ASCII].  That standard
     defines US-ASCII, but RFC 2045 [46] 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.
  'iso-10646-ucs-2':  ISO 10646 Universal Multiple-Octet Coded
     Character Set (UCS) represented as two octets (UCS-2), with the
     high order octet of each pair coming first (so-called Big Endian
     integer).

Some attribute descriptions MAY place additional requirements on
charset values that may be used, such as MANDATORY values that MUST be

                        Expires July 16, 1998

supported or additional restrictions, such as requiring that the
charset have US-ASCII as a subset charset.

4.1.10 'naturalLanguage'

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

                        Expires June 19, 1998

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

The maximum length of naturalLanguage values used within IPP is 63
octets.

4.1.11 '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
parameter, depending on the specification of the Media Type in the
IANA Registry [IANA-MT]. Examples:

  '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 SHALL mean US-ASCII
     rather than simply unspecified) [RFC2046].
  'text/plain; charset=US-ASCII':  A plain text document in US-ASCII
     [52, 56].
  '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 [RFC2044]
  'text/plain, charset=iso-10646-ucs-2':  A plain text document in
     ISO 10646 represented in two octets (UCS-2) [ISO10646-1]
  'application/postscript':  A PostScript document [RFC2046]
  'application/vnd.hp-PCL':  A PCL document [IANA-MT] (charset escape
     sequence embedded in the document data)
  'application/octet-stream':  Auto-sense - see below

                        Expires July 16, 1998

One special type is 'application/octet-stream'.  If the Printer object
supports this value, the Printer object SHALL be capable of auto-
sensing the format of the document data.  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 SHALL rely on the supplied attribute, rather than
trust its auto-sensing algorithm.  To summarize:

                        Expires June 19, 1998

  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 SHALL trust
     the client supplied value more than the outcome of applying an
     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 SHALL 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 SHALL 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.

The maximum length of a 'mimeMediaType' value in IPP is 63 octets.

4.1.12 '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.

                        Expires July 16, 1998

4.1.13 'boolean'

The 'boolean' attribute syntax is similar to an enum with only two
values:  'true' and 'false'.

4.1.14 '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.

                        Expires June 19, 1998
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.

4.1.15 '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.

4.1.16 'dateTime'

The 'dateTime' attribute syntax is a standard, fixed length, 11 octet
representation of the "DateAndTime" syntax as defined in RFC 1903
[RFC1903].  RFC 1903 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.

4.1.17 'resolution'

The 'resolution' attribute syntax specifies a two-dimensional
resolution in the indicated units.  It consists of 3 integers: 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

                        Expires July 16, 1998

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).

                        Expires June 19, 1998

4.1.18 '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 SHALL NOT be empty (i.e., a set of
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 SHALL 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 SHALL support neither an "xxx-
     default" attribute nor an "xxx-supported" attribute, and it SHALL
     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 "orientations-
     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,

                        Expires July 16, 1998
     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.

     Note: 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.

     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

                        Expires June 19, 1998
     "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

                        Expires July 16, 1998

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 3.2.1.2.

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") shows the name and syntax for each Job Template
attribute in the Printer object (the default value attribute and the
supported values attribute).  A "No" in the table means the Printer
SHALL NOT support the attribute (that is, the attribute is simply not

                        Expires June 19, 1998
applicable).  For brevity in the table, the 'text' and 'name' entries
do not show (MAX).

                        Expires June 19, July 16, 1998
  +===================+======================+======================+
  | 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-       |
  | (type4 keyword |  |  default             | supported            |
  |    name)          |  (type4 keyword |    |(1setOf               |
  |                   |    name)             | type4 keyword | name)|
  +-------------------+----------------------+----------------------+
  | job-sheets        | job-sheets-default   |job-sheets-supported  |
  | (type4 keyword |  | (type4 keyword |     |(1setOf               |
  |    name)          |    name)             | type4 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))    | (integer (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 (0:MAX)) | (integer (0:MAX))    |(1setOf integer       |
  |                   |                      | (0:MAX) |            |
  |                   |                      |  rangeOfInteger      |
  |                   |                      |   (0:MAX))           |
  +-------------------+----------------------+----------------------+
  | orientation orientation-      |orientation-requested-|orientation-requested-|
  |  requested        | orientation-default  default             | orientation-  supported           |
  |   (type2 enum)    |  (type2 enum)        | supported            |
  |                   |                      |  (1setOf type2 enum) |
  +-------------------+----------------------+----------------------+
  | media             | media-default        | media-supported      |
  | (type4 keyword |  | (type4 keyword |     |(1setOf               |
  |    name)          |    name)             | type4 keyword | name)|
  |                   |                      |                      |

                        Expires June 19, July 16, 1998
  |                   |                      | media-ready          |
  |                   |                      |(1setOf               |
  |                   |                      | type4 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)   |
  +-------------------+----------------------+----------------------+
  | compression       | No                   | compression-supported|
  | (type3 keyword)   |                      |(1setOf type3 keyword)|
  +-------------------+----------------------+----------------------+
  | job-k-octets      | No                   |job-k-octets-supported|
  | (integer (0:MAX)) |                      | (rangeOfInteger      |
  |                   |                      |      (0:MAX))        |
  +-------------------+----------------------+----------------------+
  | job-              | No                   | job-impressions-     |
  | impressions       |                      | supported            |
  | (integer (0:MAX)) |                      | (rangeOfInteger      |
  |                   |                      |      (0:MAX))        |
  +-------------------+----------------------+----------------------+
  | job-media-        | No                   | job-media-sheets-    |
  | sheets            |                      | supported            |
  | (integer (0:MAX)) |                      | (rangeOfInteger)    |
  |                   |                      |      (0:MAX))        |
  +-------------------+----------------------+----------------------+

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 SHALL
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 SHALL 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/1.0, they SHALL have priorities higher than
100, rather than restricting the range available to end-users.

                        Expires June 19, 1998

If the client does not supply this attribute and this attribute is
supported by the Printer object, the Printer object SHALL 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 SHALL take the value supplied by the
client and map it to the closest integer in a sequence of n integers
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.

                        Expires July 16, 1998

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 (type4 keyword | name (MAX))

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

Standard values for named time periods are:

  'no-hold': immediately, if there are not other reasons to hold the
     job
  '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)

                        Expires June 19, 1998

An administrator SHALL associate allowable print times with a named
time period (by means outside IPP/1.0).  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 SHALL add the 'job-hold-until-specified' value to
the job's "job-state-reasons" attribute, move the job to the 'pending-
held' state, and SHALL NOT schedule the job for printing until the
specified time-period arrives.  When the specified time period
arrives, the Printer SHALL remove the 'job-hold-until-specified' value
from the job's "job-state-reason" attribute and, if there are no other
job state reasons that keep the job in the 'pending-held' state, the
Printer SHALL consider the job as a candidate for processing by moving
the job to the 'pending' state.

                        Expires July 16, 1998

If this job attribute value is the named value 'no-hold', or the
specified time period has already started, the job SHALL 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 SHALL 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 (type4 keyword | name(MAX))

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

Standard 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.

Note: 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.

                        Expires June 19, 1998

4.2.4 multiple-document-handling (type2 keyword)

This attribute is relevant only if a job consists of two or more
documents. 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
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 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) SHALL be treated as a single

                        Expires July 16, 1998
     sequence of media sheets for finishing operations; that is,
     finishing would be performed on the concatenation of the
     sequences a(*),b(*).  The Printer object SHALL 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 SHALL be a(*), b(*),
     a(*), b(*), ..., and the Printer object SHALL force each copy
     (a(*),b(*)) to 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
     SHALL 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 SHALL 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 SHALL 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 SHALL 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 SHALL 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 SHALL be a(*), b(*), a(*), b(*), ... .

                        Expires June 19, 1998

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_ "finishings" attribute
specifies `staple', 'staple', then with 'single-document', documents a and b are
stapled together as a single document, 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 15.5.

                        Expires July 16, 1998

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 15.5.

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.

Standard values are:

  Value   Symbolic Name and Description

  '3'     'none':  Perform no finishing

                        Expires June 19, 1998
  '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."

Note: The effect of this attribute on jobs with multiple documents is
controlled by the "multiple-document-handling" job attribute (section

                        Expires July 16, 1998

4.2.4) and the relationship of this attribute and the other attributes
that control document processing is described in section 15.5.

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 SHALL be in ascending order, for
example: 1-3, 5-7, 15-19 and SHALL 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 SHALL reject the
request and return the 'client-error-bad-request' status code.

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 SHALL 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.

                        Expires June 19, 1998
When "multiple-document-handling" is 'separate-document-uncollated-
copies' or 'separate-document-collated-copies', the Printer object
SHALL 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.

                        Expires July 16, 1998

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 15.5.

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 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'.

                        Expires June 19, 1998

'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 15.5.

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

  Value   Description

                        Expires July 16, 1998
  '1'     The Printer SHALL 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 SHALL 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 SHALL 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 15.5.

4.2.10 orientation orientation-requested (type2 enum)

This attribute specifies indicates the desired orientation of for printed print-
stream pages; it does not describe the content orientation of the print-
stream pages to be printed.  In most cases, client-
supplied print-stream pages.

For some document formats (such as 'application/postscript'), the
desired orientation of the
content print-stream pages is specified within the
document format data.  This information is generated by the a device driver at prior
to the submission of the print time. However, some job.  Other document formats (such as
'text/plain') do not support include the notion of page orientation, and desired orientation within
the document data.  In the latter case it is possible for the Printer
object to bind the desired orientation after to the document content data after it
has been

                        Expires June 19, 1998

generated. 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 provides an end user with since section 4.2, item 1, points out that a
Printer object may support or not support any Job Template attribute
based on the means to
specify orientation document format supplied by the client.  However, a
special mention is made here since it is very likely that a Printer
object will supported "orientation-requested" for such documents. only a subset of the
supported document formats.

Standard values are:

  Value   Symbolic Name and Description

  '1'

                        Expires July 16, 1998
  '3'     'portrait':  The content will be imaged across the short
               edge of the medium.
  '2'
  '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
  '3'
  '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
               shsort 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 15.5.

4.2.11 media (type4 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 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

                        Expires July 16, 1998

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

                        Expires June 19, 1998
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 SHALL merge with the document data
as its prints each page.

Standard values are (taken from ISO DPA and the Printer MIB) 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 15.5.

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 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

                        Expires July 16, 1998

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 MANDATORY attribute

                        Expires June 19, 1998
that MUST be supported by Printer objects.  If it is not indicated as
MANDATORY, then it is OPTIONAL.  The maximum size in octets for 'text'
and 'name' attributes is indicated in parenthesizes.

                        Expires June 19, July 16, 1998

+----------------------------+----------------------+----------------+
|      Attribute             |     Syntax           |   MANDATORY?   |
+----------------------------+----------------------+----------------+
| job-uri                    | uri                  |  MANDATORY     |
+----------------------------+----------------------+----------------+
| job-id                     | integer(1:MAX)       |  MANDATORY     |
+----------------------------+----------------------+----------------+
| job-printer-uri            | uri                  |  MANDATORY     |
+----------------------------+----------------------+----------------+
| job-more-info              | uri                  |                |
+----------------------------+----------------------+----------------+
| job-name                   | name (MAX)           |  MANDATORY     |
+----------------------------+----------------------+----------------+
| job-originating-user-name  | name (MAX)           |  MANDATORY     |
+----------------------------+----------------------+----------------+
| job-state                  | type1 enum           |  MANDATORY     |
+----------------------------+----------------------+----------------+
| job-state-reasons          | 1setOf type2 keyword |                |
+----------------------------+----------------------+----------------+
| job-state-message          | text (MAX)           |                |
+----------------------------+----------------------+----------------+
| number-of-documents        | integer (0-MAX)      |                |
+----------------------------+----------------------+----------------+
| containing-printer-uri     | uri                  |  MANDATORY     |
+----------------------------+----------------------+----------------+
| output-device-assigned     | name (127)           |                |
+----------------------------+----------------------+----------------+
| time-at-creation           | integer (0:MAX)      |                |
+----------------------------+----------------------+----------------+
| time-at-processing         | integer (0:MAX)      |                |
+----------------------------+----------------------+----------------+
| time-at-completed          | integer (0:MAX)      |                |
+----------------------------+----------------------+----------------+
| number-of-intervening-jobs | integer (0:MAX)      |                |
+----------------------------+----------------------+----------------+
| job-message-from-operator  | text (127)           |                |
+----------------------------+----------------------+----------------+
| compression                | type3 keyword        |                |
+----------------------------+----------------------+----------------+
| 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)      |                |

                        Expires June 19, 1998
+----------------------------+----------------------+----------------+
| attributes-charset         | charset              |  MANDATORY     |

                        Expires July 16, 1998

+----------------------------+----------------------+----------------+
| attributes-natural-language| naturalLanguage      |  MANDATORY     |
+----------------------------+----------------------+----------------+

4.3.1 job-uri (uri)

This MANDATORY attribute contains the URI for the job.  The Printer
object, on receipt of a new job, generates a URI which identifies the
new Job on that Printer object. 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, however the URI MUST
reference the access method that supports the correct security
characteristics.  That is if the create request comes in over a secure
channel, the new Job URI MUST use the same secure channel.  This can
guaranteed because the Printer object returns is responsible for generating
this URI and the value Printer object MUST be aware of the "job-uri" attribute its security
configuration and policy as well as part of the response to a Printer URI used in the create
request. The precise format of a Job URI is implementation dependent.

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

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

This MANDATORY 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 used
for compatibility with SNMP index values which cannot be 0.

For a description of this attribute and its relationship to the
previous "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 MANDATORY 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

                        Expires July 16, 1998

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.

4.3.4

4.3.5 job-name (name(MAX))

This MANDATORY 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,

                        Expires June 19, 1998
the "job-name" operation attribute is not supplied by the client in
the create request, the Printer object, on creation of the Job, SHALL
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
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.

4.3.5

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

This MANDATORY 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 Section 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 operation.

4.3.6

                        Expires July 16, 1998

4.3.7 job-state (type1 enum)

This MANDATORY attribute identifies the current state of the job.
Even though the IPP protocol defines eight values for job states,
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 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 SHALL

                        Expires June 19, 1998
               indicate why the job is no longer a candidate for
               processing.

  '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'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

                        Expires July 16, 1998
               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

                        Expires June 19, 1998
               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 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, SHALL be removed, but
               the `canceled-by-xxx', 'canceled-by-xxx', if present, SHALL 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, SHALL be removed, but the 'aborted-
               by-system' value, if present, SHALL remain.

                        Expires July 16, 1998
  '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 SHALL 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.

The following figure shows the normal job state transitions.

                        Expires June 19, 1998

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

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

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

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

Implementation of these values is OPTIONAL, i.e., a Printer NEED NOT
implement them, even if (1) the output device supports the
functionality represented by the reason and (2) is available to the
Printer object implementation.  These values MAY be used with any job
state or states for which the reason makes sense.  Furthermore, when
implemented, the Printer SHALL return these values when the reason

                        Expires July 16, 1998

applies and SHALL 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 SHALL 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.

The following standard 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.

                        Expires June 19, 1998
  'job-incoming':  The CreateJob operation has been accepted by the
     Printer, but the Printer is expecting additional Send-Document
     and/or Send-URI operations and/or is accessing/accepting document
     data.
  '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.
  'job-outgoing':  The Printer is transmitting the job to the output
     device.
  '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 SHALL NOT be a candidate for processing
     until this reason is removed and there are no other reasons to
     hold the job.
  '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'.

                        Expires July 16, 1998
  '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-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.
  '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

                        Expires June 19, 1998
     authorized end-user, such as a member of the job owner's security
     group.
  '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.
  'job-canceled-at-device':  The job was canceled by an unidentified
     local user, i.e., a user at a console at the device.
  '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.
  '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.

     This reason is recommended to be used in conjunction with the
     'processing' job state to indicate that the Printer object is
     still performing some actions on the job while the job remains in
     the 'processing' 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.

                        Expires July 16, 1998
  '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.
  'job-completed-with-warnings':  The job completed with warnings.
  'job-completed-with-errors':  The job completed with errors (and
     possibly warnings too).

4.3.8

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 SHALL be able to
generate this message in any of the natural languages identified by
the Printer's "generated-natural-language-supported" attribute (see

                        Expires June 19, 1998
the "attributes-natural-language" operation attribute specified in
Section 3.1.3.1). 3.1.4.1).

Note:  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, a new attribute with keyword values, needs to be
developed and registered.

4.3.9

4.3.10 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.

4.3.10 containing-printer-uri (uri)

This MANDATORY attribute identifies the Printer object that contains
this Job object, i.e., the URI of the Printer object to which the job
was submitted.  This attribute permits a client to query the Printer
object to which the job was submitted given only the Job URI.

4.3.11 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

                        Expires July 16, 1998

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 support multiple
devices (so called "fan-out").

4.3.12 time-at-creation (integer(0:MAX))

This attribute indicates the point in time at which the Job object was
created.  In order to populate this attribute, the Printer object uses

                        Expires June 19, 1998
the value in its "printer-up-time" attribute at the time the Job
object is created.

4.3.13 time-at-processing (integer(0:MAX))

This attribute indicates the point in time at which the Job object
began processing.  In order to populate this attribute, the Printer
object uses the value in its "printer-up-time" attribute at the time
the Job object is moved into the 'processing' state for the first
time.

4.3.14 time-at-completed (integer(0:MAX))

This attribute indicates the point in time at which the Job object
completed (or was cancelled or aborted).  In order to populate this
attribute, the Printer object uses the value in its "printer-up-time"
attribute at the time the Job object is moved into the 'completed' or
'canceled' or 'aborted' state.

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 compression (type3 keyword)

This attribute identifies the compression algorithm used on the
document data.  The value of this attribute does not apply to the
encoding of the IPP operation itself.

Standard values are :

  'none': no compression is used.

                        Expires June 19, July 16, 1998
  'deflate':  ZIP public domain inflate/deflate) compression
     technology
  `gzip' GNU zip compression technology described in RFC 1952.
  'compress': UNIX compression technology

4.3.18

4.3.17 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 SHALL be rounded up, so that a job between 1 and 1024
octets SHALL be indicated as being 1, 1025 to 2048 SHALL be 2, etc.

This value SHALL 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 SHALL 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.

Note: This attribute and the following two attributes ("job-
impressions" and "job-media-sheets") are not intended to be counters;
they are intended to be useful routing and scheduling information if
known.  For these three 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 three attributes either right at
job submission time or at any later point in time.

4.3.19

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

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

As with "job-k-octets", this value SHALL not include the
multiplicative factors contributed by the number of copies specified

                        Expires June 19, 1998
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

                        Expires July 16, 1998

the size of the document(s) measured in impressions independent of the
number of copies.

As with "job-k-octets", this value SHALL 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.

See the Note in the "job-k-octets" attribute that also applies to this
attribute.

4.3.20

4.3.19 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 SHALL 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".

See the Note in the "job-k-octets" attribute that also applies to this
attribute.

4.3.21

4.3.20 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 SHALL be
rounded up, so that a job between 1 and 1024 octets inclusive SHALL be
indicated as being 1, 1025 to 2048 inclusive SHALL be 2, etc.

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

                        Expires June 19, 1998
by processing the data for each copy, the final value SHALL be a
multiple of the value of the "job-k-octets" attribute.

                        Expires July 16, 1998

Note: This attribute and the following two attributes ("job-
impressions-completed" and "job-sheets-completed") are intended to be
counters. That is, the value for a job that has not started processing
SHALL 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.

4.3.22

4.3.21 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.

See the note in "job-k-octets-processed" which also applies to this
attribute.

4.3.23

4.3.22 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.

See the note in "job-k-octets-processed" which also applies to this
attribute.

4.3.24

4.3.23 attributes-charset (charset)

This MANDATORY 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 3.1.3 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 SHALL convert from
whatever the internal charset is to that being requested in an
operation as specified in Section 3.1.3. 3.1.4.

                        Expires June 19, July 16, 1998

4.3.25

4.3.24 attributes-natural-language (naturalLanguage)

This MANDATORY 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 3.1.3 3.1.4 for a complete
description of the "attributes-natural-language" operation attribute.
See Section 3.2.6 for how this attribute is returned in a Get-Jobs
operation when jobs with different natural languages are returned.
See Sections 4.1.2 and 4.1.4 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 MANDATORY for a Printer object to
support.  If they are not indicated as MANDATORY, 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 specification.

                        Expires June 19, July 16, 1998

+----------------------------+----------------------+----------------+
|      Attribute             |     Syntax           |   MANDATORY?   |
+----------------------------+----------------------+----------------+
| printer-uri printer-uri-supported      | 1setOf uri           |  MANDATORY     |
+----------------------------+----------------------+----------------+
| printer-tls-uri uri-security-supported     | uri 1setOf type2 keyword |  MANDATORY     |
+----------------------------+----------------------+----------------+
| printer-name               | name (127)           |  MANDATORY     |
+----------------------------+----------------------+----------------+
| 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           |  MANDATORY     |
+----------------------------+----------------------+----------------+
| printer-state-reasons      | 1setOf type2 keyword |                |
+----------------------------+----------------------+----------------+
| printer-state-message      | text (MAX)           |                |
+----------------------------+----------------------+----------------+
| operations-supported       | 1setOf type2 enum    |  MANDATORY     |
+----------------------------+----------------------+----------------+
| charset-configured         | charset              |  MANDATORY     |
+----------------------------+----------------------+----------------+
| charset-supported          | 1setOf charset       |  MANDATORY     |
+----------------------------+----------------------+----------------+
| natural-language-configured| naturalLanguage      |  MANDATORY     |
+----------------------------+----------------------+----------------+
| generated-natural-language-| 1setOf               |  MANDATORY     |
| supported                  |   naturalLanguage    |                |
+----------------------------+----------------------+----------------+
| document-format-default    | mimeMediaType        |  MANDATORY     |
+----------------------------+----------------------+----------------+
| document-format-           | 1setOf               |  MANDATORY     |
|   supported                |   mimeMediaType      |                |
+----------------------------+----------------------+----------------+
| printer-is-accepting-jobs  | boolean              |  MANDATORY     |
+----------------------------+----------------------+----------------+
| queued-job-count           | integer (0:MAX)      |                |
+----------------------------+----------------------+----------------+

                        Expires June 19, July 16, 1998

| printer-message-from-      | text (127)           |                |
| operator                   |                      |                |
+----------------------------+----------------------+----------------+
| color-supported            | boolean              |                |
+----------------------------+----------------------+----------------+
| reference-uri-schemes-     | 1setOf uriScheme     |                |
|   supported                |                      |                |
+----------------------------+----------------------+----------------+
| pdl-override pdl-override-supported     | type2 keyword        |  MANDATORY     |
+----------------------------+----------------------+----------------+
| printer-up-time            | integer (1:MAX)      |  MANDATORY     |
+----------------------------+----------------------+----------------+
| printer-current-time       | dateTime             |                |
+----------------------------+----------------------+----------------+
| multiple-operation-time-out| integer (1:MAX)      |                |
+----------------------------+----------------------+----------------+
| compression-supported      | 1setOf type3 keyword |                |
+----------------------------+----------------------+----------------+
| job-k-octets-supported     | rangeOfInteger       |                |
|                            |    (0:MAX)           |                |
+----------------------------+----------------------+----------------+
| job-impressions-supported  | rangeOfInteger       |                |
|                            |    (0:MAX)           |                |
+----------------------------+----------------------+----------------+
| job-media-sheets-supported | rangeOfInteger       |                |
|                            |    (0:MAX)           |                |
+----------------------------+----------------------+----------------+

4.4.1 printer-uri printer-uri-supported (uri)

This MANDATORY Printer attribute contains at least one URI for the
Printer object.  It OPTIONALLY contains more than one URI for the
Printer
object when not using Transport Layer Security (TLS). object.    An administrator determines a printer's URI Printer object's
URI(s) and configures this attribute to that URI (by contain those URIs by some
means outside the scope of IPP/1.0). IPP/1.0.  The precise format of this URI is
implementation dependent and depends on the protocol.  See
section 8.2.  See protocol.  See the next
section for a description "uri-security-supported" which is the
MANDATORY companion attribute 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-security-supported (1setOf type2 keyword)

This MANDATORY 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

                        Expires July 16, 1998

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. The following standard
values are defined:

  'none': There are no secure communication channel protocols in use
     for the given URI.
  'tls': TLS 1.0 [TLS] is the "printer-tls-uri" attribute secure communications channel protocol
     in 4.4.2.

4.4.2 printer-tls-uri (uri)

This MANDATORY Printer attribute contains use for the URI given URI.
  'ssl3': SSL3 is the secure communications channel protocol in use
     for the Printer
object when using Transport Layer Security (TLS). given URI.

Consider the following example.  An administrator
determines a printer's URI and configures the
"printer-uri-supported" and "uri-security-supported" attributes as
follows:

  "printer-uri-supported": 'http://acme.com/open-printer',
     'http://acme.com/password-printer', 'http://acme.com/private-
     printer', 'https://acme.com/private-printer'
  "uri-security-supported": 'none', 'none', 'tls', 'ssl3'

In this attribute to case, one Printer object has four URIs.

  - For the first URI, 'http://acme.com/open-printer', the value
     'none' in "uri-security-supported" indicates that URI
(by means outside of IPP/1.0). there is no
     secure channel protocol configured to run under HTTP.  The precise format of this URI name
     implies that there is
implementation dependent and depends on no Basic or Digest authentication being
     used, but it is up to the client to determine that while using
     HTTP underneath the IPP application protocol.  See section
8.2.

                        Expires June 19, 1998

Both
  - For the "printer-uri" and second URI, 'http://acme.com/password-printer', the "printer-tls-uri" attributes are
MANDATORY for an IPP Printer value
     'none' in "uri-security-supported" indicates that there is no
     secure channel protocol configured to support. run under HTTP.  However,
     in this case the system
administrator MAY choose to configure (by means outside the scope of
IPP/1.0) only one name does imply that there is some sort of the attributes, depending on site policy..  The
other attribute, which Basic
     or Digest authentication being used within HTTP.  But again, it
     is not configured, SHALL have up to the special out-
of-band value: 'no-value' (see client to determine that while using HTTP and by
     processing any '401 Unauthorized' HTTP error messages.
  - For the beginning of section 4.1).

Note:  It is expected third URI, 'http://acme.com/private-printer', the value
     'tls' in "uri-security-supported" indicates that most IPP Printer objects will be configured
for only TLS access or non-TLS access, however the system
administrator MAY choose is being
     used to configure both secure the "printer-uri" and
"printer-tls-uri" attributes channel.  The client SHOULD be prepared to allow for both use
     TLS access and non-TLS
access.

Also, for simplicity, framing to negotiate an acceptable ciphersuite to use while
     communicating with the majority of Printer object.  In this document uses just case, the
"printer-uri" attribute when describing name
     implies the purpose and behavior use of a
Printer's identifying attribute no matter its 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 configuration.
Therefore, anyplace it must use by following naming
     conventions or by parsing the URI to determine which security
     mechanisms are implied.

                        Expires July 16, 1998
  - For the fourth URI, 'https://acme.com/private-printer', the value
     'ssl3' in "uri-security-supported" indicates that this document describes a client supplying SSL3 is being
     used to secure the "printer-uri" attribute, channel.  Notice that the client MUST supply URI is the "printer-tls-
uri" attribute same as
     the URI in its place when accessing the third case (except for the scheme), however this
     time, the client SHOULD be prepared to use SSL3 framing to
     negotiate an IPP object using TLS.
In response acceptable ciphersuite to a Get-Printer-Attributes request, use while communicating
     with the IPP Printer
object returns whichever attribute the client requested.  If object.  As in the
client requested 'all' or 'printer-description' attribute groups, both third case, the "printer-uri" presence of a
     secure channel and which security mechanism to use is made
     explicit by the "printer-tls-uri" attributes are returned,
since both are presence of the 'ssl3' value in "uri-security-
     supported".

It is expected that many IPP Printer object attributes.  The client objects will be able configured to
support only one channel (either configured to
determine use TLS access or not),
and will therefore only ever have one URI listed in the "printer-uri-
supported" attribute.  No matter the configuration of the IPP Printer by inspecting the
values of the two attributes checking to see if either is un-
configured (i.e., the un-configured attribute is set to
object (whether it has only one URI or more than one URI), a client
SHALL supply only one URI in the special
out-of-band value 'no-value'). target "printer-uri" operation
attribute.

4.4.3 printer-name (name(127))

This MANDATORY Printer attribute contains the name of the Printer
object.  It is a name that is more user end-user friendly than the value of the
"printer-uri" attribute. 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.

4.4.4 printer-location (text(127))

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

                        Expires June 19, 1998
XYZ".

4.4.5 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".

                        Expires July 16, 1998

4.4.6 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.

4.4.7 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 IPP.  The device manufacturer may initially
populate this attribute.

4.4.8 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.

4.4.9 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.

                        Expires June 19, 1998

4.4.10 printer-state (type1 enum)

This MANDATORY 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.

                        Expires July 16, 1998

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/1.0.  A Printer NEED NOT implement all
values if they are not applicable to a given implementation.

The following standard values are defined:

  Value   Symbolic Name and Description

  '3'     'idle':  If a Printer receives a job (whose required
               resources are ready) while in this state, such a job
               SHALL transit into the processing state immediately.
               If the printer-state-reasons attribute contains any
               reasons, they SHALL be reasons that would not prevent a
               job from transiting into the processing state
               immediately, e.g., toner-low. Note: if a Printer
               controls more than one output device, the above
               definition implies that a Printer is idle if at least
               one output device is idle.

  '4'     'processing':  If a Printer receives a job (whose required
               resources are ready) while in this state, such a job
               SHALL transit into the pending state immediately. Such
               a job SHALL transit into the processing state only
               after jobs ahead of it complete.  If the printer-state-
               reasons attribute contains any reasons, they SHALL be
               reasons that do not prevent the current job from
               printing, e.g. toner-low.  Note: if a Printer controls
               more than one output device, the above definition
               implies that a Printer is processing if at least one
               output device is processing, and none is idle.

  '5'     'stopped':  If a Printer receives a job (whose required
               resources are ready) while in this state, such a job
               SHALL transit into the pending state immediately. Such
               a job SHALL transit into the processing state only
               after some human fixes the problem that stopped the
               printer and after jobs ahead of it complete printing.
               The "printer-state-reasons" attribute SHALL contain at
               least one reason, e.g. media-jam, which prevents it

                        Expires June 19, 1998
               from either processing the current job or transitioning
               a pending job to the processing state.

               Note: if a Printer controls more than one output
               device, the above definition implies that a Printer is
               stopped only if all output devices are stopped.  Also,
               it is tempting to define stopped as when a sufficient

                        Expires July 16, 1998
               number of output devices are stopped and leave it to an
               implementation to define the sufficient number.  But
               such a rule complicates the definition of stopped and
               processing. For example, with this alternate definition
               of stopped, a job can move from idle to processing
               without human intervention, even though the Printer is
               stopped.

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

This Printer attribute supplies additional detail about the device's
state.

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 SHALL 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 SHALL
     contain nothing that prevents a job from completing, though in
     some cases the output may be of lower quality.
  - '-error': This suffix indicates that the reason is an "error".
     An implementation SHALL include all errors. If this attribute
     contains one or more errors, printer SHALL be in the stopped
     state.

If the implementation does not add any one of the three suffixes, all
parties SHALL 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

                        Expires June 19, 1998
'stopped', then there MUST be an error reason among the values in the
"printer-state-reasons" attribute.

The following standard values are defined:

  'other': The device has detected an error other than one listed in
     this document.

                        Expires July 16, 1998
  'none': There are not reasons. This state reason is semantically
     equivalent to "printer-state-reasons" without any value.
  'media-needed': A tray has run out of media.
  'media-jam': The device has a media jam.
  'paused': Someone has paused the Printer object.  In this state, a
     Printer SHALL not produce printed output, but it SHALL perform
     other operations requested by a client.  If a Printer had been
     printing a job when the Printer was paused, the Printer SHALL
     resume printing that job when the Printer is no longer paused and
     leave no evidence in the printed output of such a pause.
  'shutdown': Someone has removed a Printer object from service, and
     the device may be powered down or physical removed.  In this
     state, a Printer object SHALL not produce printed output, and
     unless the Printer object is realized by a print server that is
     still active, the Printer object SHALL 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

                        Expires June 19, 1998
     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.
  'marker-supply-low': The device is low on marker supply (ink,
     paint, etc.).
  'spool-area-full': The limit of persistent storage allocated for
     spooling has been reached.
  'cover-open': One or more covers on the device are open.

                        Expires July 16, 1998
  '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.
  '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)

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

This Printer attribute specifies the additional information about the
printer state and printer state reasons in human readable text.  If
the Printer object supports this attribute, the Printer object SHALL
be able to generate this message in any of the natural languages
identified by the Printer's "generated-natural-language-supported"

                        Expires June 19, 1998
attribute (see the "attributes-natural-language" operation attribute
specified in Section 3.1.3.1). 3.1.4.1).

4.4.13 operations-supported (1setOf type2 enum)

This MANDATORY Printer attribute specifies the set of supported
operations for this Printer object and contained Job objects.  No 32-

                        Expires July 16, 1998

bit enum value for this attribute SHALL exceed 0x8FFF, since these
values are passed in two octets in each Protocol request [IPP-PRO].

The following standard values are defined:

  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-0x3FFF       reserved for future operations
  0x4000-0x8FFF       reserved for private extensions

This allows for certain vendors to implement private extensions that
are guaranteed to not conflict with future registered extensions.
However, there is no guarantee that two or more private extensions
will not conflict.

4.4.14 charset-configured (charset)

This MANDATORY 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 SHALL also be among the values of the Printer object's
"charset-supported" attribute.

                        Expires June 19, 1998

4.4.15 charset-supported (1setOf charset)

This MANDATORY 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' SHALL
be present, since IPP objects MUST support the UTF-8 [RFC2044]
charset.  If a Printer object supports a charset, it means that for

                        Expires July 16, 1998

all attributes of syntax 'text' and 'name' the IPP object SHALL (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 SHALL
perform charset conversion between the charsets as described in
Section 3.2.1.2.

4.4.16 natural-language-configured (naturalLanguage)

This MANDATORY 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
3.1.3.1
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 SHALL also be among the values
of the Printer object's "generated-natural-language-supported"
attribute.

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

This MANDATORY 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 SHALL accept in requests 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 3.1.4) 3.1.5) in

                        Expires June 19, 1998
operation responses, the Printer and Job objects SHALL be able to
generate messages in any of the Printer's supported natural languages.
See section 3.1.3 3.1.4 for the specification of 'text' and 'name'
attributes in operation requests and responses.

                        Expires July 16, 1998

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

4.4.18 document-format-default (mimeMediaType)

This 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 4.1.11.

4.4.19 document-format-supported (1setOf mimeMediaType)

This 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 4.1.11.

4.4.20 printer-is-accepting-jobs (boolean)

This MANDATORY 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.

Note: 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 may cause
the Printer to reject jobs when the "printer-state" is 'idle' or it
may cause the Printer object to accepts jobs when the "printer-state"
is 'stopped'.

                        Expires June 19, 1998

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

This 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.

                        Expires July 16, 1998

4.4.22 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.

4.4.23 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/1.0).

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

4.4.24 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 values:

  'ftp':  The Printer object will use an FTP 'get' operation.  If the
     URI does not indicate a name or password in the URI itself, the
     Printer object will use anonymous FTP generating (if prompted) a
     password.  Since many FTP servers require that anonymous FTP
     logins supply a password in the form a valid Internet email
     address, the Printer object MUST be able to generate such a
     password (syntactically correct, yet perhaps semantically
     meaningless) if needed.

The Printer object MAY OPTIONALLY support other URI schemes (see
section 4.1.8).

                        Expires June 19, 1998

4.4.25 pdl-override pdl-override-supported (type2 keyword)

This MANDATORY 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 values:

                        Expires July 16, 1998
  - '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.

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

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

This MANDATORY Printer attribute indicates the amount of time (in
seconds) that this instance of this Printer implementation has been up
and running.  This value is used to populate the Job attributes "time-
at-creation", "time-at-processing", and "time-at-completed".  These
time values are all measured in seconds and all have meaning only
relative to this attribute, "printer-up-time".  The value is a
monotonically increasing value starting from 1 when the Printer object
is started-up (initialized, booted, etc.).

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 the first case, the Printer SHOULD not tweak any existing related
Job attributes ("time-at-creation", "time-at-processing", and "time-
at-completed").  In the second case, the Printer object SHOULD reset
those attributes to 0.  If a client queries a time-related Job
attribute and finds the value to be 0, the client MUST assume that the
Job was submitted in some life other than the Printer's current life.

                        Expires June 19, 1998

4.4.27 printer-current-time (dateTime)

This Printer attribute indicates the current absolute wall-clock time.
If an implementation supports this attribute, then a client could
calculate the absolute wall-clock time each Job's "time-at-creation",
"time-at-processing", and "time-at-completed" attributes by using both
"printer-up-time" and this attribute, "printer-current-time".  If an
implementation does not support this attribute, a client can only

                        Expires July 16, 1998

calculate the relative time of certain events based on the MANDATORY
"printer-up-time" attribute.

4.4.28 multiple-operation-time-out (integer(1:MAX))

This Printer attributes identifies how long (in seconds) the Printer
object waits for additional Send-Document or Send-URI operations to
follow a still-open multi-document Job object before taking one of the
actions indicated in section 3.3.1.

4.4.29 compression-supported (1setOf type3 keyword)

This 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 values are :

  'none': no compression is used.
  'deflate':  ZIP public domain inflate/deflate) compression
     technology
  'gzip' GNU zip compression technology described in RFC 1952
     [RFC1952].
  'compress': UNIX compression technology

4.4.30 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.

4.4.31 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 4.3.18.

                        Expires July 16, 1998

4.4.32 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 4.3.19.

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

A conforming client SHALL support all MANDATORY operations as defined
in this document.  For each attribute included in an operation
request, a conforming client SHALL 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 registered
extensions and/or private extensions in an operation request, as long
as they 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.

                        Expires June 19, 1998

When sending a request, an IPP client NEED NOT supply any attributes
that are indicated as OPTIONALLY supplied by the client.

A client SHALL 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.  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.

                        Expires July 16, 1998

A query response may contain attribute groups, attributes, and values
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 extended registered or
private attributes and/or attribute values that conform to Section 6.
Clients may choose to ignore any parameters, attributes, or values
that it does not understand.

5.2 IPP Object Conformance Requirements

This section specifies the conformance requirements for conforming
implementations with respect to objects, operations, and attributes.

5.2.1 Objects

Conforming implementations SHALL implement all of the model objects as
defined in this specification in the indicated sections:

  Section 2.1 - Printer Object
  Section 2.2 - Job Object

5.2.2 Operations

Conforming IPP object implementations SHALL implement all of the
MANDATORY model operations, including mandatory responses, as defined
in this specification in the indicated sections:

  For a Printer object:
     Print-Job (section 3.2.1)          MANDATORY
     Print-URI (section 3.2.2)          OPTIONAL
     Validate-Job (section 3.2.3)       MANDATORY
     Create-Job (section 3.2.4)         OPTIONAL
     Get-Printer-Attributes (section 3.2.5)  MANDATORY
     Get-Jobs (section 3.2.6)           MANDATORY

                        Expires June 19, 1998

  For a Job object:
     Send-Document (section 3.3.1)      OPTIONAL
     Send-URI (section 3.3.2)           OPTIONAL
     Cancel-Job (section 3.3.3)         MANDATORY
     Get-Job-Attributes (section 3.3.4) MANDATORY

Conforming IPP objects SHALL support all MANDATORY operation
attributes and all values of such attributes if so indicated in the
description.  Conforming IPP objects SHALL ignore all unsupported or
unknown operation attributes or operation attribute groups received in

                        Expires July 16, 1998

a request, but SHALL reject a request that contains a supported
operation attribute that contains an unsupported value.

The following section on object attributes specifies the support
required for object attributes.

5.2.3 IPP Object Attributes

Conforming IPP objects SHALL support all of the MANDATORY object
attributes, as defined in this specification in the indicated
sections.

If an object supports an attribute, it SHALL 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 SHALL support at least one of the specified
values and at most all of them.

5.2.4 Extensions

A conforming IPP object MAY support registered extensions and private
extensions, as long as they meet the requirements specified in Section
6.

For each attribute included in an operation response, a conforming IPP
object SHALL return a value whose type and value syntax conforms to
the requirement of the Model document as specified in Sections 3 and
4.

5.2.5 Attribute Syntaxes

An IPP object SHALL 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 IPP/1.0).

                        Expires June 19, 1998
Furthermore, an IPP object SHALL 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.

5.3 Charset and Natural Language Requirements

All clients and IPP objects SHALL support the 'utf-8' charset as
defined in section 4.1.9.

                        Expires July 16, 1998

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
3.1.3).
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.

5.4 Security Conformance Requirements

Conforming IPP Printer objects MAY support Transport Layer Security
(TLS) access, support access without TLS or support both means of
access.

Conforming IPP clients MUST SHOULD support TLS access and non-TLS access.
Note: This client requirement to support both means that conforming
IPP clients will be able to inter-operate with any IPP Printer object.

For a detailed discussion of security considerations and the IPP
application security profile required for TLS support, see section 8.

6. IANA Considerations (registered and private extensions)

This section describes how IPP can be extended. extended, and it is aligned with
the guidelines as set forth by the IESG [IANA-CON].

6.1 Typed Extensions

IPP allows for "keyword" and "enum" extensions (see sections 4.1.5 and
4.1.6).  In reviewing proposals for such extensions, the IPP Subject
Matter Experts are: Carl-Uno Manros (manros@cp10.es.xerox.com) and
Steve Zilles (szilles@adobe.com).  If a replacement is needed, the
IESG Applications Area Director, in consultation with the PWG [PWG]
using pwg@pwg.org, SHALL appoint a replacement.  The PWG can also
specify a replacement at any time.

This document uses prefixes to the "keyword" and "enum" basic syntax
type in order to communicate extra information to the reader through

                        Expires June 19, 1998
its name. This extra information need not be represented in an

                        Expires July 16, 1998

implementation because it is unimportant to a client or Printer.  The
list below describes the prefixes and their meaning.

  "type1":  The IPP standard must be revised to add a new keyword or
     a new enum.  No private keywords or enums are allowed.

  "type2":  Implementers can, at any time, add new keyword or enum
     values by proposing the specification to:

     - the IPP working group (IPP WG using ipp@pwg.org) while it is
       still chartered, or
     - the Printer Working Group [PWG] using pwg@pwg.org after the IPP
       working group is disbanded

     who will review the proposal and work with IANA to register the
     additional keywords and enums.   IANA  For enums, the IPP WG or PWG
     assigns the number for next available unused number.  When a type 2 keyword
     or enum
     values and is approved by the IPP WG or PWG, the PWG becomes the
     point of contact for any future maintenance that might be
     required for that registration.  IANA keeps the registry of
     keywords and enums. enums as it does for any registration.

  "type3":  Implementers can, at any time, add new keyword and enum
     values by submitting the complete specification directly to IANA,
     no the
     IPP Subject Matter Experts.  While no IPP working group or
     Printer Working Group review is required, the IPP Subject Matter
     Experts may, at their discretion, forward the proposal to the IPP working group
     WG or Printer Working Group review is required.
     IANA PWG for advice and comment.  For enums, the IPP Subject
     Matter Experts  assigns the number for enum values values. and keeps the
     registry of keywords and enums.  IANA  When a type 3 keyword or enum is responsible
     approved by IPP Subject Matter Experts, the original proposer
     becomes the point of contact for ensuring new any future maintenance that
     might be required for that registration.  IANA keeps the registry
     of keywords are unique. and enums as it does for any registration.

  "type4":  Anyone (system administrators, system integrators, site
     managers, etc.) can, at any time, add new installation-defined
     values (keywords, but not enum values) to a local system. Care
     SHOULD be taken by the implementers to see that keywords do not
     conflict with other keywords defined by the standard or as
     defined by the implementing product. There is no registration or
     approval procedure for type 4 keywords.

Note: Attributes with type 4 keywords also allow the 'name' attribute
syntax for administrator defined names.  Such names are not
registered.

                        Expires July 16, 1998

By definition, each of the four types above assert some sort of
registry or review process in order for extensions to be considered
valid.  Each higher level (1, 2, 3, 4) 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 type4 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 specification defines keyword and enum values for all of the
above types, including type4 keywords.

                        Expires June 19, 1998

For private (unregistered) keyword extensions, implementers SHOULD use
keywords with a suitable distinguishing prefix, such as "xxx-" where
xxx 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 private
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 private (unregistered) enum extension, implementers SHALL use
values in the reserved integer range which is 2**30 to 2**31-1.

6.2 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.  RFC 2045 [RFC2045]
defines the syntax for valid Internet media types.  IANA is the
registry for all Internet media types.

6.3 Attribute Extensibility

Attribute names 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.

                        Expires July 16, 1998

6.4 Attribute Syntax Extensibility

Attribute syntaxes 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.  The
value codes that identify each of the attribute syntaxes are assigned
in the protocol specification [IPP-PRO].

                        Expires June 19, 1998

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.). 4.1.3).

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
  - requests the charset and natural language for attributes returned
     by the IPP object in operation responses (as described in Section
     3.1.3.1).
     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 for the 'text' attribute syntax in
Section 4.1.1. section 4.1.2 and 4.1.4 respectively.

All IPP objects SHALL support the UTF-8 [RFC2044] charset in all
'text' and 'name' attributes supported.  If an IPP object supports
more than the UTF-8 charset, the object SHALL convert between them in
order to return the requested charset to the client according to
Section 3.1.3.2. 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 3.1.3.1). 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 SHALL 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 returned.

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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.

                        Expires June 19, 1998
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
'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" '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'. '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 (i.e., (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 (i.e., (e.g.,
     the Printer object's "printer-name" attribute). and "printer-location"
     attributes).  These too can be in any natural language.  If the
     natural language for these attributes is different than what a

                        Expires July 16, 1998
     client requests, then they must be reported using the Natural
     Language Override mechanism.
  3. Some attributes are supplied by the device manufacturer (i.e., (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 (i.e., (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.

                        Expires June 19, 1998
  5. Some attributes are generated by the IPP object (i.e., (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
     respond in 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

  Job Attributes:
     job-name (name)               client or Printer object
     job-originating-user-name (name)   Printer object
     job-state-message (text)      Job or Printer object
     job-message-from-operator (text)   operator

  Printer Attributes:
     printer-name (name)           administrator
     printer-location (text)       administrator
     printer-info (text)           administrator
     printer-make-and-model (text) administrator or manufacturer
     printer-state-message (text)  Printer object
     printer-message-from-operator (text)    operator

                        Expires July 16, 1998

8. Security Considerations

Some IPP objects MAY be deployed over protocol stacks that support
Transport Layer Security (TLS) Version 1.0.  Other IPP objects MAY be
deployed over protocol stacks that do not support TLS.  Some IPP
objects MAY be deployed over both types of protocol stacks.  Those IPP
objects that support TLS, are capable of supporting mutual
authentication as well as privacy of messages via multiple encryption

                        Expires June 19, 1998
schemes.  TLS 1.0 also supports a backwards compatibility mode for
negotiating down to SSL3 which leverages the vast installed base of
SSL3 aware clients and servers.  An important point about security
related information for TLS access to an IPP object, is that the
security-related parameters (authentication, encryption keys, etc.)
are "out-of-band" to the actual IPP protocol.

An IPP object that does not support TLS MAY elect to support a
transport layer that provides other security mechanisms.  For example,
in a mapping of IPP over HTTP/1.1 [IPP-PRO], if the IPP object does
not support TLS, HTTP still allows for client authentication.

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/1.0, 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

                        Expires July 16, 1998

information back to a client about any potential access control
violations for an IPP object.

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 any given IPP
system administrator may be concerned with cannot be anticipated, IPP

                        Expires June 19, 1998
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. TLS Version
1.0 supports the type of negotiated levels of security required by
most, if not all, potential IPP environments. IPP environments that
require no security can elect to deploy IPP objects that do not
utilize the optional TLS security mechanisms.

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

                        Expires July 16, 1998

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.

                        Expires June 19, 1998

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.
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" will not be specified for version 1 of IPP.

8.2 URIs for TLS and non-TLS Access

As described earlier, an IPP object can provide support TLS access, non-TLS
access, or both.  The "printer-uri" "printer-uri-supported" attribute contains the
Printer object's URI for non-TLS access.  A different URI(s).  Its companion attribute, "uri-security-
supported", identifies the "printer-
tls-uri" attribute, contains security mechanism used for each URI listed
in the "printer-uri-supported" attribute.  For each Printer object's operation
request, a client SHALL supply only one URI for TLS access. 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 The "requesting-user-name" Operation Attribute

Each operation SHALL specify the user who is performing the operation
in both of the following two ways:

  1) via the MANDATORY "requesting-user-name" operation attribute
     that a client SHOULD supply in all operations. The client SHALL
     obtain the value for this attribute from an environmental or
     network login name for the user, rather than allowing the user to
     supply any value. If the client does not supply a value for

                        Expires July 16, 1998
     "requesting-user-name", the printer SHALL assume that the client
     is supplying some anonymous name, such as "anonymous".
  2) via an authentication mechanism of the underlying transport
     which may be configured to give no authentication information.

There are six cases to consider:

  a)  the authentication mechanism gives no information, and the
     client doesn't specify  "requesting-user-name".
  b)  the authentication mechanism gives no information, but the
     client specifies "requesting-user-name".
  c)  the authentication mechanism specifies a user which has no
     human readable representation, and the client  doesn't specify
     "requesting-user-name".

                        Expires June 19, 1998
  d)  the authentication mechanism specifies a user which has no
     human readable representation, but the client specifies
     "requesting-user-name".
  e)  the authentication mechanism specifies a user which has a human
     readable representation. The Printer object ignores the
     "requesting-user-name".
  f)  the authentication mechanism specifies a user who is trusted
     and whose name means that the value of the "requesting-user-
     name", which MUST be present, is treated as the authenticated
     name.

Note:  Case "f" is intended for a tightly coupled gateway and server
to work together so that the "user" name is able to be that of the
gateway client and not that of the gateway.  Because most, if not all,
system vendors will initially implement IPP via a gateway into their
existing print system, this mechanism is necessary unless the
authentication mechanism allows a gateway (client) to act on behalf of
some other client.

The user-name has two forms:

  - one that is human readable: it is held in the MANDATORY "job-
     originating-user-name" Job Description attribute which is set
     during the job creation operations. It is used for presentation
     only, such as returning in queries or printing on start sheets
  - one for authorization: it is held in an undefined (by IPP) Job
     object attribute which is set by the job creation operation.  It
     is used to authorize other operations, such as Send-Document,
     Send-URI, Cancel-Job, to determine the user when the my-jobs'
     attribute is specified with Get-Jobs, and to limit what
     attributes and values to return with Get-Job-Attributes and Get-Jobs. Get-
     Jobs.

The human readable user name:

                        Expires July 16, 1998
  - is the value of the "requesting-user-name" for cases b, d and f.
  - comes from the authentication mechanism for case e
  - is some anonymous name, such as "anonymous" for cases a and c.

The user name used for authorization:

  - is the value of the "requesting-user-name" for cases b  and f.
  - comes from the authentication mechanism for cases c, d and  e
  - is some anonymous name, such as "anonymous" for case a.

The essence of these rules for resolving conflicting sources of user-
names is that a printer implementation is free to pick either source
as long as it achieves consistent results.  That is, if a user uses
the same path for a series of requests, the requests MUST appear to
come from the same user from the standpoint of both the human-readable
user name and the user name for authorization.  This rule MUST
continue to apply even if a request could be authenticated by two or
more mechanisms.  It doesn't matter which the of  several authentication
mechanism
mechanisms a Printer uses as long as it achieves consistent results.
If a client uses more than one authentication mechanism, it is
recommended that an administrator make all credentials resolve to the
same user and user-name as much as possible.

                        Expires June 19, 1998

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 IPP Security Application Profile for TLS

The IPP application profile for TLS follows the standard "Mandatory
Cipher Suites" requirement as documented in the TLS specification
[TLS].  Client implementations MUST NOT assume any other cipher suites
are supported by an IPP Printer object.

If a conforming IPP object supports TLS, it MUST implement and support
the "Mandatory Cipher Suites" as specified in the TLS specification
and MAY support additional cipher suites.

                        Expires July 16, 1998

A conforming IPP client SHOULD support TLS, and it MUST implement and
support TLS  including the "Mandatory
Cipher Suites" as specified in the TLS
specification and specification.  A conforming
IPP client MAY support additional cipher suites.

It is possible that due to certain government export restrictions some
non-compliant versions of this extension could be deployed.
Implementations wishing to inter-operate with such non-compliant
versions MAY offer the TLS_DHE_DSS_EXPORT_WITH_DES40_CBC_SHA
mechanism.  However, since 40 bit ciphers are known to be vulnerable
to attack by current technology, any client which actives a 40 bit
cipher MUST NOT indicate to the user that the connection is completely
secure from eavesdropping.

9. References

 [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.

                        Expires June 19, 1998

[CS-POL]
     H. Alvestrand, "IETF Policy on Character Sets and Languages, work
     in progress <draft-alvestrand-charset-policy-01.txt>, August 29,
     1997.

[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

[IANA-CON]
     Narte, T. and Alverstran, H.T.:  Guidelines for Writing an IANA
     Considerations Section in RFCs, Work in Progress, draft-iest-
     iana-considerations-01.txt.

 [IANA-CS]
     IANA Registry of Coded Character Sets: ftp://ftp.isi.edu/in-
     notes/iana/assignments/character-sets

[IANA-CSa]
     N. Freed, J. Postel:  IANA CharSet Registration Procedures, Work
     in Progress (draft-freed-charset-reg-02.txt).

[IANA-MT]
     IANA Registry of Media Types:  ftp://ftp.isi.edu/in-
     notes/iana/assignments/media-types/

                        Expires July 16, 1998

[IPP-PRO]
     Herriot, R., Butler, S., Moore, P., Tuner, R., " Internet
     Printing Protocol/1.0: Protocol Specifications", draft-ipp-pro-
     03.txt, draft-ietf-ipp-
     pro-05.txt, November, 1997.

[IPP-RAT]
     Zilles, S., "Rationale for the Structure and Model and Protocol
     for the Internet Printing Protocol", draft-ipp-rat-01.txt, draft-ietf-ipp-rat-02.txt,
     November, 1997.

[IPP-REQ]
     Wright, D., "Requirements for an Internet Printing Protocol",
     draft-ipp-req-01.txt,
     draft-ietf-ipp-req-.txt, November, 1997.

[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.

                        Expires June 19, 1998

 [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]
     P. Mockapetris, "DOMAIN NAMES - IMPLEMENTATION AND
     SPECIFICATION", RFC 1035, November 1987.

                        Expires July 16, 1998

[RFC1179]
     McLaughlin, L. III, (editor), "Line Printer Daemon Protocol" RFC
     1179, August 1990.

 [RFC1630]
     T. Berners-Lee, "Universal Resource Identifiers in WWW: A
     Unifying Syntax for the Expression of Names and Addresses of
     Objects on the Network as used in the World-Wide Web", RFC 1630,
     June 1994.

[RFC1738]
     Berners-Lee, T., Masinter, L., McCahill, M. , "Uniform Resource
     Locators (URL)", RFC 1738, December, 1994.

[RFC1759]
     Smith, R., Wright, F., Hastings, T., Zilles, S., and Gyllenskog,
     J., "Printer MIB", RFC 1759, March 1995.

[RFC1766]
     H. Alvestrand, " Tags for the Identification of Languages", RFC
     1766, March 1995.

[RFC1952]
     P. Deutsch, "GZIP file format specification version 4.3", RFC
     1952, May 1996.

[RFC2044]
     F. Yergeau, "UTF-8, a transformation format of Unicode and ISO
     10646", RFC 2044, October 1996.

                        Expires June 19, 1998

[RFC2068]
     R. Fielding, J. Gettys, J. Mogul, H. Frystyk, T. Berners-Lee,
     "Hypertext Transfer Protocol - HTTP/1.1", RFC 2068, January 1997

[RFC2069]
     J. Franks, P. Hallam-Baker, J. Hostetler, P. Leach, A. Luotonen,
     E. Sink, L. Stewart, "An Extension to HTTP: Digest Access
     Authentication", RFC-2069, Jan 1997.

 [RFC2045]
     N. Fried, N. Borenstein, ", Multipurpose Internet Mail Extensions
     (MIME) Part One: Format of Internet Message Bodies " RFC 2045,
     November 1996.

[RFC2046]
     Multipurpose Internet Mail Extensions (MIME) Part Two: Media
     Types. N. Freed & N. Borenstein. November 1996. (Obsoletes
     RFC1521, RFC1522, RFC1590), RFC 2046.

                        Expires July 16, 1998

[RFC2048]
     Multipurpose Internet Mail Extension (MIME) Part Four:
     Registration Procedures. N. Freed, J. Klensin & J. Postel.
     November 1996. (Format: TXT=45033 bytes) (Obsoletes RFC1521,
     RFC1522, RFC1590) (Also BCP0013), RFC 2048.

[RFC2119]
     S. Bradner, "Key words for use in RFCs to Indicate Requirement
     Levels", RFC 2119 , March 1997

[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. Copyright Notice

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

                        Expires June 19, 1998
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.

11. Author's Address

     Scott A. Isaacson (Editor)
     Novell, Inc.
     122 E 1700 S

                        Expires July 16, 1998
     Provo, UT   84606

     Phone: 801-861-7366
     Fax:   801-861-2517
     e-mail: sisaacson@novell.com

     Tom Hastings
     Xerox Corporation
     701 S. Aviation Blvd.
     El Segundo, CA   90245

     Phone: 310-333-6413
     Fax:   310-333-5514
     e-mail: hastings@cp10.es.xerox.com

     Robert Herriot
     Sun Microsystems Inc.
     901 San Antonio.Road, MPK-17
     Palo Alto, CA 94303

     Phone: 650-786-8995
     Fax:  650-786-7077
     e-mail: robert.herriot@eng.sun.com

     Roger deBry
     HUC/003G
     IBM Corporation
     P.O. Box 1900

                        Expires June 19, 1998
     Boulder, CO 80301-9191

     Phone: (303) 924-4080
     Fax: (303) 924-9889
     e-mail: debry@vnet.ibm.com

     Patrick Powell
     San Diego State University
     9475 Chesapeake Dr., Suite D
     San Diego, CA  95123

     Phone: (619) 874-6543
     Fax: (619) 279-8424
     e-mail: papowell@sdsu.edu

     IPP Mailing List:  ipp@pwg.org
     IPP Mailing List Subscription: ipp-request@pwg.org
     IPP Web Page:  http://www.pwg.org/ipp/

                        Expires July 16, 1998

Implementers of this specification 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
     Jeff Barnett - IBM
     Ron Bergman - Dataproducts Corp.
     Sylvan Butler, HP
     Keith Carter, IBM Corporation
     Jeff Copeland - QMS
     Andy Davidson - Tektronix
     Mabry Dozier - QMS
     Lee Farrell - Canon Information Systems
     Steve Gebert - IBM
     Babek Jahromi, Microsoft
     David Kellerman - Northlake Software
     Rick Landau - Digital
     Greg LeClair - Epson
     Harry Lewis - IBM
     Pete Loya - HP
     Ray Lutz - Cognisys
     Mike MacKay, Novell, Inc.
     Carl-Uno Manros, Xerox, Corp.
     Jay Martin - Underscore
     Stan McConnell - Xerox
     Ira McDonald, High North Inc.
     Paul Moore, Microsoft
     Tetsuya Morita - Ricoh
     Yuichi Niwa - Ricoh
     Pat Nogay - IBM
     Ron Norton - Printronics

                        Expires June 19, 1998
     Bob Pentecost - HP
     Rob Rhoads - Intel
     Xavier Riley - Xerox, Corp.
     David Roach - Unisys
     Stuart Rowley, Kyocera
     Hiroyuki Sato - Canon
     Bob Setterbo - Adobe
     Devon Taylor, Novell, Inc.
     Mike Timperman - Lexmark
     Randy Turner - Sharp
     Atsushi Yuki - Kyocera
     Rick Yardumian - Xerox, Corp.
     Lloyd Young - Lexmark
     Bill Wagner - DPI

                        Expires July 16, 1998
     Jim Walker - DAZEL
     Chris Wellens - Interworking Labs
     Rob Whittle - Novell
     Don Wright - Lexmark
     Peter Zehler, Xerox, Corp.
     Steve Zilles, Adobe

                        Expires June 19, July 16, 1998

12. APPENDIX A: Terminology

This specification uses the terminology defined in this section.

12.1 Conformance Terminology

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and  "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [RFC2119]. The
sections below reiterate these definitions and include some additional
ones.

12.1.1 MUST

This word, or the terms "REQUIRED",  "SHALL" or "MANDATORY", means
that the definition is an absolute requirement of the specification.

12.1.2 MUST NOT

This phrase, or the phrase "SHALL NOT", means that the definition is
an absolute prohibition of the specification.

12.1.3 SHOULD

This word, or the adjective "RECOMMENDED", means that there may exist
valid reasons in particular circumstances to ignore a particular item,
but the full implications must be understood and carefully weighed
before choosing a different course.

12.1.4 SHOULD NOT

This phrase, or the phrase "NOT RECOMMENDED" means that there may
exist valid reasons in particular circumstances when the particular
behavior is acceptable or even useful, but the full implications
should be understood and the case carefully weighed before
implementing any behavior described with this label.

                        Expires June 19, July 16, 1998

12.1.5 MAY

This word, or the adjective "OPTIONAL", means that an item is truly
optional.  One vendor may choose to include the item because a
particular marketplace requires it or because the vendor feels that it
enhances the product while another vendor may omit the same item.   An
implementation which does not include a particular option MUST be
prepared to inter-operate with another implementation which does
include the option, though perhaps with reduced functionality. In the
same vein an implementation which does include a particular option
MUST be prepared to inter-operate with another implementation which
does not include the option (except, of course, for the feature the
option provides.)

12.1.6 NEED NOT

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 4.1.5).  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 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.

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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
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 protocol specification document [IPP-PRO] 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

                        Expires June 19, July 16, 1998

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.

A conforming implementation SHALL support all MANDATORY attributes.
However, even for MANDATORY 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' SHALL 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' SHALL 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.

                        Expires June 19, July 16, 1998

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 IPP.  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.

                        Expires June 19, July 16, 1998

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.  For
error type status codes, 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

Since IPP status codes are type2 enums, they are extensible.  IPP
clients are NOT REQUIRED to understand the meaning of all registered
status codes, though such understanding is obviously desirable.
However, applications SHALL 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 shall 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

                        Expires June 19, July 16, 1998

information which will help to explain the unusual status.  The name
of the enum is the suggested status message for US English.

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 private use within each status code class.
Values 0x0600 to 0x7FFF are reserved for future assignment and SHALL
not be used.

13.1 Status Codes

Each status code is described below. Section 13.2 contains a table
that indicates which status codes apply to which operations.  Sections
15.3 and 15.4 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/1.0 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.

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13.1.2.2 successful-ok-ignored-or-substituted-attributes (0x0001)

The request has succeeded, but some attributes were ignored or
unsupported values were substituted with supported values in order to
process the job without rejecting it.

13.1.2.3 successful-ok-conflicting-attributes (0x0002)

The request has succeeded, but some attribute values conflicted with
the values of other 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.

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/1.0 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.

13.1.4.1 client-error-bad-request (0x0400)

The request could not be understood by the IPP object due to malformed
syntax.  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.

                        Expires June 19, July 16, 1998

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.

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.

                        Expires June 19, July 16, 1998

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.

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.

                        Expires June 19, July 16, 1998

13.1.4.10 client-error-request-uri-too-long (0x0409)

The IPP object is refusing to service the request because the request
URI or the "document-uri" is longer than the IPP object is willing to
interpret.  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 SHALL return this status code, even if there are
other attributes that are not supported as well, since this error is a
bigger problem than with Job Template attributes.

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 or attribute values supplied in the request and the
client supplied the "ipp-attributes-fidelity" operation attribute with
the 'true' value, the Printer object shall return this status code.
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 an optional attribute and the attribute itself is not even
supported by the Printer.  If the "ipp-attribute-fidelity" attribute
is 'false', the Printer SHALL ignore or substitute values for
unsupported 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.

                        Expires June 19, July 16, 1998

13.1.4.13 client-error-uri-scheme-not-supported (0x040C)

The type of the client supplied URI in a Print-URI or a Send-URI
operation is not supported.

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 SHALL reject the operation and return this
status (see Section 3.1.3.1). 3.1.4.1).

13.1.4.15 client-error-conflicting-attributes (0x040E)

The request is rejected because some attribute values conflicted with
the values of other attributes.

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.

                        Expires June 19, July 16, 1998

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-
internal-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 used in the request message.  The IPP object
is indicating that it is unable or unwilling to complete the request
using the same version as supplied in the request other than with this
error message. The response should contain a Message describing why
that version is not supported and what other versions are supported by
that IPP object.

A conforming IPP/1.0 client SHALL specify the valid version ('1.0') on
each request.  A conforming IPP/1.0 object SHALL NOT return this
status code to a conforming IPP/1.0 client.  An IPP object SHALL
return this status code to a non-conforming IPP client.  The response
SHALL identify a in the "version-number" operation attribute the closest
version number that the IPP object does support.

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.

                        Expires June 19, July 16, 1998

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.

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-not-accepting-jobs" attribute to 'false' (by
means outside of IPP/1.0).

                        Expires June 19, July 16, 1998

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

                                               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  x  x  x  x x  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-uri-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
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  x  x

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]):

                        Expires June 19, July 16, 1998
  'default': The default medium for the output device
  'iso-a4-white': Specifies the ISO A4 white medium
  'iso-a4-colored': Specifies the ISO A4 colored medium
  'iso-a4-transparent' Specifies the ISO A4 transparent medium
  'iso-a3-white': Specifies the ISO A3 white medium
  'iso-a3-colored': Specifies the ISO A3 colored medium
  'iso-a5-white': Specifies the ISO A5 white medium
  'iso-a5-colored': Specifies the ISO A5 colored medium
  'iso-b4-white': Specifies the ISO B4 white medium
  'iso-b4-colored': Specifies the ISO B4 colored medium
  'iso-b5-white': Specifies the ISO B5 white medium
  'iso-b5-colored': Specifies the ISO B5 colored medium
  'jis-b4-white': Specifies the JIS B4 white medium
  'jis-b4-colored': Specifies the JIS B4 colored medium
  'jis-b5-white': Specifies the JIS B5 white medium
  'jis-b5-colored': Specifies the JIS B5 colored medium

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

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

                        Expires June 19, July 16, 1998
  '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 (white-only):

  '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
  'iso-a1-white': Specifies the ISO A1 white medium
  'iso-a2-white': Specifies the ISO A2 white medium
  'iso-a6-white': Specifies the ISO A6 white medium
  'iso-a7-white': Specifies the ISO A7 white medium
  'iso-a8-white': Specifies the ISO A8 white medium
  'iso-a9-white': Specifies the ISO A9 white medium
  'iso-10-white': Specifies the ISO A10 white medium
  'iso-b0-white': Specifies the ISO B0 white medium
  'iso-b1-white': Specifies the ISO B1 white medium
  'iso-b2-white': Specifies the ISO B2 white medium
  'iso-b3-white': Specifies the ISO B3 white medium
  'iso-b6-white': Specifies the ISO B6 white medium
  'iso-b7-white': Specifies the ISO B7 white medium
  'iso-b8-white': Specifies the ISO B8 white medium
  'iso-b9-white': Specifies the ISO B9 white medium
  'iso-b10-white': Specifies the ISO B10 white medium
  'jis-b0-white': Specifies the JIS B0 white medium
  'jis-b1-white': Specifies the JIS B1 white medium
  'jis-b2-white': Specifies the JIS B2 white medium
  'jis-b3-white': Specifies the JIS B3 white medium
  'jis-b6-white': Specifies the JIS B6 white medium
  'jis-b7-white': Specifies the JIS B7 white medium
  'jis-b8-white': Specifies the JIS B8 white medium
  'jis-b9-white': Specifies the JIS B9 white medium
  'jis-b10-white': Specifies the JIS B10 white medium

The following standard values are defined for engineering media:

                        Expires June 19, July 16, 1998
  'a': Specifies the engineering A size medium
  'b': Specifies the engineering B size medium
  'c': Specifies the engineering C size medium
  'd': Specifies the engineering D size medium
  'e': Specifies the engineering E size medium

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

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

                        Expires June 19, July 16, 1998
  '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
  '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
  '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

                        Expires June 19, July 16, 1998
  '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
  'jis-b9': Specifies the JIS B9 size: 45mm x 64mm
  'jis-b10': Specifies the JIS B10 size: 32mm x 45mm

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.

The following sections describe how these two types of conflicts are
handled in the IPP model.

                        Expires June 19, July 16, 1998

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 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 SHALL 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'):

  - If the client supplies 'false' or does not supply the attribute,
     the Printer object SHALL always accept the request by ignoring
     unsupported Job Template attributes and by substituting

                        Expires June 19, July 16, 1998
     unsupported values of supported Job Template attributes with
     supported values.
  - If the client supplies 'true', the Printer object SHALL 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
that
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 IPP/1.0.

This MANDATORY Printer attribute takes on the following values:

                        Expires June 19, July 16, 1998
  - '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 Generate an output device specific command sequence to realize
     the feature represented by the IPP attribute value value.
  2) parse 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 value.
  3) indicate 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 interpreter.
  4) anything 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) Actually modify Parse the document data and replace the conflicting embedded instructions to correspond to
     instruction with a new embedded instruction that approximates,
     but does not match, the
     semantics semantic intent of the client-supplied IPP attributes. attribute
     value.

Note:  The "ipp-attribute-fidelity" attribute applies to the Printer's
ability to either accept or reject other unsupported Job 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

                        Expires July 16, 1998

these attributes actually affect the processing of the Job when the
document data contains embedded instructions depends on the ability of

                        Expires June 19, 1998
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 Suggested Operation Processing Steps for All Operations

When an IPP object receives a request, the IPP object either accepts
or rejects the request. In order to determine whether or not to accept
or reject the request, the IPP object SHOULD execute the following
steps.  The order of the steps may be rearranged and/or combined,
including making one or multiple passes over the request.  Therefore,
the error status codes returned may differ between implementations.
The next section contains the additional steps for the Print-Job,
Validate-Job, Print-URI, Create-Job, Send-Document, and Send-URI
operations that create jobs, adds documents, and validates jobs.

In the following, processing continues step by step until a "RETURNS
the xxx status code _" statement is encountered.  Error returns are
indicated by the verb: "REJECTS".  Since clients have difficulty
getting the status code, code before sending all of the document data in a
Print-Job request, clients SHOULD use the Validate-Job operation
before sending large documents to be printed, in order to validate
whether the IPP Printer will accept the job or not.

It is assumed that security authentication and authorization has
already taken place at a lower layer.

15.3.1 Validate version number

Every request and every response contains the "version-number"
attribute.  The value of this attribute is the major and minor version
number of the syntax and semantics that the client and IPP object is
using, respectively, respectively.  The "version-number" attribute remains in a
fixed position across all future versions so that all clients and IPP
object that support future versions can determine which version is the same for all
versions.
being used.  The IPP object checks to see if the major version number

                        Expires July 16, 1998

supplied in the request is supported.  If not, the Printer object
REJECTS the request and RETURNS the 'server-error-version-not-
supported' status code in the response.  The IPP object returns in the
fixed version number field in the
"version-number" response what attribute the major and minor version is for
the error response.  Thus the client can learn at least

                        Expires June 19, 1998 one major and
minor version that the IPP object supports.  The IPP object is
encouraged to return the closest version number to the one supplied by
the client.

The checking of the minor version number is implementation dependent,
however if the client supplied minor version is explicitly supported,
the IPP object SHALL respond using that identical minor version
number.  If the requested minor version is not supported (the
requested minor version is either higher or lower lower) than
the highest a supported
minor version, the IPP object SHOULD return the
highest closest supported
minor version.  In either case, both the client and
the IPP object are guaranteed to communicated up to at least the level
of the common major version.

15.3.2 Validate operation code identifier

The Printer object checks to see if the operation "operation-id" attribute
supplied by the client is supported as indicated in the Printer
object's "printer-operations-supported" attribute.  If not, the
Printer REJECTS the request and returns the
'server-error-operation-not-supported' 'server-error-operation-
not-supported' status code in the response.

Note:  Validating

15.3.3 Validate the version number request identifier

The Printer object checks to see if the "request-id" attribute
supplied by the client is in range.  If the value is not between 1 and operation
2**31 - 1 (inclusive), the  Printer object REJECTS the request and
returns the 'client-error-bad-request' status code requires that
these fields be in the response.

Note: The "version-number",  attribute,   "operation-id", and the
"request-id" attributes in the same fixed octet positions in all
versions of the protocol.  These fields are validated before
proceeding with the rest of the validation.

15.3.3

15.3.4 Validate attribute group and attribute presence and order

The order of the following validation steps depends on implementation.

15.3.3.1

                        Expires July 16, 1998

15.3.4.1 Validate the presence and order of attribute groups

Client requests and IPP object responses contain attribute groups that
Section 3 requires to be present and in a specified order.  An IPP
object verifies that the attribute groups are present and in the
correct order in requests supplied by clients (attribute groups
without an * in the following tables).

If an IPP object receives a request with (1) required attribute groups
missing, or (2) the attributes groups are out of order, or (3) the
groups are repeated, the IPP object REJECTS the request and RETURNS
the 'client-error-bad-request' status code.  For example, it is an
error for the Job Template Attributes group to occur before the
Operation Attributes group, for the Operation Attributes group to be
omitted, or for an attribute group to occur more than once, except in
the Get-Jobs response.

                        Expires June 19, 1998

Since this kind of attribute group error is most likely to be an error
detected by a client developer rather than by a customer, the IPP
object NEED NOT return an indication of which attribute group was in
error in either the Unsupported Attributes group or the Status
Message.  Also, the IPP object NEED NOT find all attribute group
errors before returning this error.

15.3.3.2

15.3.4.2 Ignore unknown attribute groups in the expected position

Future attribute groups may be added to the specification at the end
of requests just before the Document Content and at the end of
response, except for the Get-Jobs response, where it maybe there or
before the first job attributes returned.  If an IPP object receives
an unknown attribute group in these positions, it ignores the entire
group, rather than returning an error, since that group may be a new
group in a later minor version of the protocol that can be ignored.
(If the new attribute group cannot be ignored without confusing the
client, the major version number would have been increased in the
protocol document and in the request).  If the unknown group occurs in
a different position, the IPP object REJECTS the request and RETURNS
the 'client-error-bad-request' status code.

Clients also ignore unknown attribute groups returned in a response.

Note:  By validating that requests are in the proper form, IPP objects
force clients to use the proper form which, in turn, increases the
chances that customers will be able to use such clients from multiple
vendors with IPP objects from other vendors.

15.3.3.3

                        Expires July 16, 1998

15.3.4.3 Validate the presence of a single occurrence of required
Operation attributes

Client requests and IPP object responses contain Operation attributes
that Section 4 3 requires to be present.  Attributes may be in any order
within a group.  An IPP object verifies that the attributes that
Section 4 requires to be supplied by the client have been supplied in
the request (attributes without an * in the following tables).  An
asterisk (*) indicates groups and Operation attributes that the client
may omit in a request or an IPP object may omit in a response.

If an IPP object receives a request with required attributes missing
or repeated from a group, the IPP object REJECTS the request and
RETURNS the 'client-error-bad-request' status code.  For example, it
is an error for the "attributes-charset" or "attributes-natural-
language" attribute to be omitted in any operation request, or for an
Operation attribute to be supplied in a Job Template group or a Job

                        Expires June 19, 1998
Template attribute to be supplied in an Operation Attribute group in a
create request.  It is also an error to supply the "attributes-
charset" attribute twice.

Since these kinds of attribute errors are most likely to be detected
by a client developer rather than by a customer, the IPP object NEED
NOT return an indication of which attribute was in error in either the
Unsupported Attributes group or the Status Message.  Also, the IPP
object NEED NOT find all attribute errors before returning this error.

The following tables list all the attributes for all the operations by
attribute group in each request and each response.  The left to right
order of the groups is the order that the client supplies the groups
as specified in Section 3.  The order of the attributes within a group
is arbitrary, though the tables below lists the attributes in the
following order with the following notation:

  (M)     MANDATORY attributes that an IPP object MUST support and
               that a client MUST supply
  (M*)    MANDATORY attributes that an IPP object MUST support, but
               that a client may omit in a request or an IPP object
               may omit in a response
  (O)     OPTIONAL attributes that an IPP object NEED NOT support
  (O*)    OPTIONAL attributes that an IPP object NEED NOT support and
               a client may omit in a request or an IPP object may
               omit in a response

                          Operation Requests

                        Expires July 16, 1998

The tables below show the attributes in their proper attribute groups
for operation requests:

Print-Job Request:
     Group 1: Operation Attributes (M)
          printer-uri (M)
          attributes-charset (M)
          attributes-natural-language (M)
          requesting-user-name (M*)
          job-name (M*)
          ipp-attribute-fidelity (M*)
          document-name (M*)
          document-format (M*)
          document-natural-language (O*)
          compression (O*)
          job-k-octets (O*)
          job-impressions (O*)
          job-media-sheets (O*)

                        Expires June 19, 1998
     Group 2: Job Template Attributes (M)
          Job Template attributes (M*) (see Section 4.2)
     Group 3: Document Content (M)
          document content

Validate-Job Request:
     Group 1: Operation Attributes (M)
          printer-uri (M)
          attributes-charset (M)
          attributes-natural-language (M)
          requesting-user-name (M*)
          job-name (M*)
          ipp-attribute-fidelity (M*)
          document-name (M*)
          document-format (M*)
          document-natural-language (O*)
          compression (O*)
          job-k-octets (O*)
          job-impressions (O*)
          job-media-sheets (O*)
     Group 2: Job Template Attributes (M)
          Job Template attributes (M*) (see Section 4.2)

Create-Job Request:
     Group 1: Operation Attributes (M)
          printer-uri (M)
          attributes-charset (M)
          attributes-natural-language (M)
          requesting-user-name (M*)
          job-name (M*)

                        Expires July 16, 1998
          ipp-attribute-fidelity (M*)
          compression (O*)
          job-k-octets (O*)
          job-impressions (O*)
          job-media-sheets (O*)
     Group 2: Job Template Attributes (M)
          Job Template attributes (M*) (see Section 4.2)

Print-URI Request:
     Group 1: Operation Attributes (M)
          printer-uri (M)
          attributes-charset (M)
          attributes-natural-language (M)
          document-uri (M)
          requesting-user-name (M*)
          job-name (M*)
          ipp-attribute-fidelity (M*)
          document-name (M*)

                        Expires June 19, 1998
          document-format (M*)
          document-natural-language (O*)
          compression (O*)
          job-k-octets (O*)
          job-impressions (O*)
          job-media-sheets (O*)
     Group 2: Job Template Attributes (M)
          Job Template attributes (M*) (see Section 4.2)

Send-Document Request:
     Group 1: Operation Attributes (M)
          (printer-uri & job-id) | job-uri (M)
          attributes-charset (M)
          attributes-natural-language (M)
          last-document (M)
          requesting-user-name (M*)
          document-name (M*)
          document-format (M*)
          document-natural-language (O*)
          compression (O*)
     Group 2: Document Content (M)
          document content

Send-URI Request:
     Group 1: Operation Attributes (M)
          (printer-uri & job-id) | job-uri (M)
          attributes-charset (M)
          attributes-natural-language (M)

          last-document (M)
          document-uri (M)

                        Expires July 16, 1998
          requesting-user-name (M*)
          document-name (M*)
          document-format (M*)
          document-natural-language (O*)
          compression (O*)

Cancel-Job Request:
     Group 1: Operation Attributes (M)
          (printer-uri & job-id) | job-uri (M)
          attributes-charset (M)
          attributes-natural-language (M)
          requesting-user-name (M*)
          message (O*)

Get-Printer-Attributes Request:
     Group 1: Operation Attributes (M)
          printer-uri (M)

                        Expires June 19, 1998
          attributes-charset (M)
          attributes-natural-language (M)
          requesting-user-name (M*)
          requested-attributes (M*)
          document-format (M*)

Get-Job-Attributes Request:
     Group 1: Operation Attributes (M)
          (printer-uri & job-id) | job-uri (M)
          attributes-charset (M)
          attributes-natural-language (M)
          requesting-user-name (M*)
          requested-attributes (M*)

Get-Jobs Request:
     Group 1: Operation Attributes (M)
          printer-uri (M)
          attributes-charset (M)
          attributes-natural-language (M)
          requesting-user-name (M*)
          limit (M*)
          requested-attributes (M*)
          which-jobs (M*)
          my-jobs (M*)

                         Operation Responses

The tables below show the response attributes in their proper
attribute groups for responses.

                        Expires July 16, 1998

Print-Job Response:
Print-URI Response:
Create-Job Response:
Send-Document Response:
Send-URI Response:
     Group 1: Operation Attributes (M)
          attributes-charset (M)
          attributes-natural-language (M)
          status-message (O*)
     Group 2: Unsupported Attributes (M*) (see Note 3)
          unsupported attributes (M*)
     Group 3: Job Object Attributes(M*) (see Note 2)
          job-uri (M)
          job-id (M)
          job-state (M)

                        Expires June 19, 1998
          job-state-reasons (O)
          job-state-message (O)
          number-of-intervening-jobs (O)

Validate-Job Response:
Cancel-Job Response:
     Group 1: Operation Attributes (M)
          attributes-charset (M)
          attributes-natural-language (M)
          status-message (O*)
     Group 2: Unsupported Attributes (M*) (see Note 3)
          unsupported attributes (M*)

Note 2 - the Job Object Attributes and Printer Object Attributes are
returned only if the IPP object returns one of the success status
codes.

Note 3 - the Unsupported Attributes Group is present only if the
client included some Operation and/or Job Template attributes that the
Printer doesn't support whether a success or an error return.

Get-Printer-Attributes Response:
     Group 1: Operation Attributes (M)
          attributes-charset (M)
          attributes-natural-language (M)
          status-message (O*)
     Group 2: Unsupported Attributes (M*) (see Note 4)
          unsupported attributes (M*)
     Group 3: Printer Object Attributes(M*) (see Note 2)
          <requested attributes> (M*)

                        Expires July 16, 1998

Note 4 - the Unsupported Attributes Group is present only if the
client included some Operation attributes that the Printer doesn't
support whether a success or an error return.

Get-Job-Attributes Response:
     Group 1: Operation Attributes (M)
          attributes-charset (M)
          attributes-natural-language (M)
          status-message (O*)
     Group 2: Unsupported Attributes (M*) (see Note 4)
          unsupported attributes (M*)
     Group 3: Job Object Attributes(M*) (see Note 2)
          <requested attributes> (M*)

Get-Jobs Response:
     Group 1: Operation Attributes (M)
          attributes-charset (M)

                        Expires June 19, 1998
          attributes-natural-language (M)
          status-message (O*)
     Group 2: Unsupported Attributes (M*) (see Note 4)
          unsupported attributes (M*)
     Group 3: Job Object Attributes(M*) (see Note 2)
          <requested attributes> (M*)

Note 5:  for the Get-Jobs operation the response contains a separate
Job Object Attributes group 2 3 to N-1 containing requested-attributes
for each job object in the response.

15.3.4

15.3.5 Validate the values of the MANDATORY Operation attributes

An IPP object validates the values supplied by the client of the
MANDATORY Operation attribute that the IPP object MUST support.  The
next section specifies the validation of the values of the OPTIONAL
Operation attributes that IPP objects MAY support.

The IPP object performs the following syntactic validation checks of
each Operation attribute value:

     a)
       that the length of each Operation attribute value is correct
       for the attribute syntax tag supplied by the client according
       to Section 4.1.
     b)
       that the attribute syntax tag is correct for that Operation
       attribute according to Section 3,
     c)
       that the value is in the range specified for that Operation
       attribute according to Section 3,

                        Expires July 16, 1998
     d)
       that multiple values are supplied by the client only for multi-valued Operation
       attributes,
       operation attributes that are multi-valued, i.e., that are
       1setOf  X according to Section 3.

If any of these checks fail, the IPP object REJECTS the request and
RETURNS the 'client-error-bad-request' status code.  Since such an
error is most likely to be an error detected by a client developer,
rather than by an end-user, the IPP object NEED NOT return an
indication of which attribute had the error in either the Unsupported
Attributes Group or the Status Message.  The description for each of
these syntactic checks is explicitly expressed in the first IF
statement in the following table.

In addition, the IPP object checks each Operation attribute value
against some Printer object attribute or some hard-coded value if
there is no "xxx-supported" Printer object attribute defined. If its
value is not among those supported or is not in the range supported,
then the IPP object REJECTS the request and RETURNS the error status
code indicated in the table by the second IF statement.  If the value
of the Printer object's "xxx-supported" attribute is 'no-value'

                        Expires June 19, 1998
(because the system administrator hasn't configured a value), the
check always fails.

-----------------------------------------------
attributes-charset (charset)
  IF NOT any single non-empty 'charset' value less than 64 octets,
     REJECT/RETURN 'client-error-bad-request'.
  IF NOT in the Printer object's "charset-supported" attribute,
     REJECT/RETURN "client-error-charset-not-supported".

attributes-natural-language(naturalLanguage)
  IF NOT any single non-empty 'naturalLanguage' value less than 64
     octets, REJECT/RETURN 'client-error-bad-request'.
  ACCEPT the request even if not a member of the set in the Printer
     object's "generated-natural-language-supported" attribute.

requesting-user-name
  IF NOT any single non-empty 'name' value less than 256 octets,
     REJECT/RETURN 'client-error-bad-request'.
  IF the IPP object can obtain a better authenticated name, use it
     instead.

job-name(name)
  IF NOT any single non-empty 'name' value less than 256 octets,
     REJECT/RETURN 'client-error-bad-request'.
  IF NOT supplied by the client, the Printer object creates a name
     from the document-name or document-uri.

                        Expires July 16, 1998

document-name (name)
  IF NOT any single non-empty 'name' value less than 256 octets,
     REJECT/RETURN 'client-error-bad-request'.

ipp-attribute-fidelity (boolean)
  IF NOT either a single 'true' or 'false' 'boolean' value equal to 1
     octet, REJECT/RETURN 'client-error-bad-request'.
  IF NOT supplied by the client, the IPP object assumes the value
     'false'.

document-format (mimeMediaType)
  IF NOT any single non-empty 'mimeMediaType' value less than 64
     octets, REJECT/RETURN 'client-error-bad-request'.
  IF NOT in the Printer object's "document-format-supported"
     attribute, REJECT/RETURN 'client-error-document-format-not-
     supported'
  IF NOT supplied by the client, the IPP object assumes the value of
     the Printer object's "document-format-default" attribute.

document-uri (uri)

                        Expires June 19, 1998
  IF NOT any single non-empty 'uri' value less than 1024 octets,
     REJECT/RETURN 'client-error-request-uri-too-long'.
  IF the URI syntax is not valid, REJECT/RETURN 'client-error-bad-
     request'.
  IF scheme is NOT in the Printer object's "reference-uri-schemes-
     supported" attribute, REJECT/RETURN 'client-error'-uri-scheme-
     not-supported'.

last-document (boolean)
  IF NOT either a single 'true' or 'false' 'boolean' value equal to 1
     octet, REJECT/RETURN 'client-error-bad-request'.

job-id (integer(1:MAX))
  IF NOT any single 'integer' value equal to 4 octets AND in the
     range 1 to MAX, REJECT/RETURN 'client-error-bad-request'.
  IF NOT a job-id of an existing Job object, REJECT/RETURN 'client-
     error-not-found' or 'client-error-gone' status code, if keep
     track of recently deleted jobs.

requested-attributes (1setOf keyword)
  IF NOT any number of 'keyword' values less than 256 octets,
     REJECT/RETURN 'client-error-bad-request'.
  Ignore unsupported values which are the keyword names of
     unsupported attributes.  Don't bother to copy such requested
     (unsupported) attributes to the Unsupported Attribute response
     group since the response will not return them.

which-jobs (type2 keyword)

                        Expires July 16, 1998
  IF NOT a single 'keyword' value less than 256 octets, REJECT/RETURN
     'client-error-bad-request'.
  IF NEITHER 'completed' NOR 'not-completed', copy the attribute and
     the unsupported value to the Unsupported Attributes response
     group and REJECT/RETURN 'client-error-attributes-or-values-not-
     supported'.
  Note: a Printer still supports the 'completed' value even if it
     keeps no completed/canceled/aborted jobs:  by returning no jobs
     when so queried.
  IF NOT supplied by the client, the IPP object assumes the 'not-
     completed' value.

my-jobs (boolean)
  IF NOT either a single 'true' or 'false' 'boolean' value equal to 1
     octet, REJECT/RETURN 'client-error-bad-request'.
  IF NOT supplied by the client, the IPP object assumes the 'false'
     value.

limit (integer(1:MAX))

                        Expires June 19, 1998
  IF NOT any single 'integer' value equal to 4 octets AND in the
     range 1 to MAX, REJECT/RETURN 'client-error-bad-request'.
  IF NOT supplied by the client, the IPP object returns all jobs, no
     matter how many.

-----------------------------------------------

15.3.5

15.3.6 Validate the values of the OPTIONAL Operation attributes

OPTIONAL Operation attributes are those that an IPP object MAY or MAY
NOT support.  An IPP object validates the values of the OPTIONAL
attributes supplied by the client.  The IPP object performs the same
syntactic validation checks for each OPTIONAL attribute value as in
Section 15.3.4. 15.3.5.  As in Section 15.3.4, 15.3.5, if any fail, the IPP object
REJECTS the request and RETURNS the 'client-error-bad-request' status
code.

In addition, the IPP object checks each Operation attribute value
against some Printer attribute or some hard-coded value if there is no
"xxx-supported" Printer attribute defined. If its value is not among
those supported or is not in the range supported, then the IPP object
REJECTS the request and RETURNS the error status code indicated in the
table.  If the value of the Printer object's "xxx-supported" attribute
is 'no-value' (because the system administrator hasn't configured a
value), the check always fails.

                        Expires July 16, 1998

If the IPP object doesn't recognize/support an attribute, the IPP
object treats the attribute as an unknown or unsupported attribute
(see the last row in the table below).

-----------------------------------------------
document-natural-language (naturalLanguage)
  IF NOT any single non-empty 'naturalLanguage' value less than 64
     octets, REJECT/RETURN 'client-error-bad-request'.
  IF NOT a value that the Printer object supports in document
     formats, (no standard "xxx-supported" Printer attribute),
     REJECT/RETURN 'client-error-natural-language-not-supported'.

compression (type3 keyword)
  IF NOT any single 'keyword' values less than 256 octets,
     REJECT/RETURN 'client-error-bad-request'.
  IF NOT in the Printer object's "compression-supported" attribute,
     copy the attribute and the unsupported value to the Unsupported
     Attributes response group and REJECT/RETURN 'client-error-
     attributes-or-values-not-supported'.

job-k-octets (integer(0:MAX))
  IF NOT any single 'integer' value equal to 4 octets,

                        Expires June 19, 1998
  REJECT/RETURN 'client-error-bad-request'.
  IF NOT in the range of the Printer object's "job-k-octets-
     supported" attribute, copy the attribute and the unsupported
     value to the Unsupported Attributes response group and
     REJECT/RETURN 'client-error-attributes-or-values-not-supported'.

job-impressions (integer(0:MAX))
  IF NOT any single 'integer' value equal to 4 octets,
  REJECT/RETURN 'client-error-bad-request'.
  IF NOT in the range of the Printer object's "job-impressions-
     supported" attribute, copy the attribute and the unsupported
     value to the Unsupported Attributes response group and
     REJECT/RETURN 'client-error-attributes-or-values-not-supported'.

job-media-sheets (integer(0:MAX))
  IF NOT any single 'integer' value equal to 4 octets,
  REJECT/RETURN 'client-error-bad-request'.
  IF NOT in the range of the Printer object's "job-media-supported"
     attribute, copy the attribute and the unsupported value to the
     Unsupported Attributes response group and REJECT/RETURN 'client-
     error-attributes-or-values-not-supported'.

message (text(127))
  IF NOT any single non-empty 'text' value less than 128 octets,
  REJECT/RETURN 'client-error-bad-request'.

                        Expires July 16, 1998

unknown or unsupported attribute
  IF the attribute syntax supplied by the client is supported but the
     length is not legal for that attribute syntax, REJECT/RETURN
     'client-error-bad-request'.
  ELSE copy the attribute and value to the Unsupported Attributes
     response group and change the attribute value to the out-of-band "out-of-
     band" 'unsupported' value, but otherwise ignore the attribute.

  Note: Future Operation attributes may be added to the protocol
  specification that may occur anywhere in the specified group.  When
  the operation is otherwise successful, the IPP object returns the
  'successful-ok-ignored-or-substituted-attributes' status code.
  Ignoring unsupported Operation attributes in all operations is
  analogous to the handling of unsupported Job Template attributes in
  the create and Validate-Job operations when the client supplies the
  "ipp-attribute-fidelity" Operation attribute with the 'false'
  value.
----------------------------------------------- This last rule is so that we can add OPTIONAL Operation
  attributes to future versions of IPP so that older clients can
  inter-work with new IPP objects and newer clients can inter-work
  with older IPP objects.

                        Expires June 19, 1998  (If the new attribute cannot be ignored
  without performing unexpectedly, the major version number would
  have been increased in the protocol document and in the request).
  This rule for Operation attributes is independent of the value of
  the "ipp-attribute-fidelity" attribute.   For example, if an IPP
  object doesn't support the OPTIONAL "job-k-
octets" attribute (because of the implementation or because of some
administrator's choice not to configure a value for the Printer
object's "job-k-octets-supported" attribute, leaving it with a 'no-
value' out-of-band value), "job-k-octets" attribute', the
  IPP object treats "job-k-octets" as an unknown attribute and only
  checks the length for the 'integer' attribute syntax supplied by
  the client.  If it is not four octets, the IPP object REJECTS the
  request and RETURNS the 'client-error-bad-
request' 'client-error-bad-request' status code,
  else the IPP object copies the attribute to the Unsupported
  Attribute response group, setting the value to the out-of-
band "out-of-band"
  'unsupported' value, but otherwise ignores the attribute.

-----------------------------------------------

15.4 Suggested Additional Processing Steps for Operations that
Create/Validate Jobs and Add Documents

This section in combination with the previous section recommends the
processing steps for the Print-Job, Validate-Job, Print-URI, Create-
Job, Send-Document, and Send-URI operations that IPP objects SHOULD
use.  These are the operations that create jobs, validate a Print-Job
request, and add documents to a job.

15.4.1 Default "ipp-attribute-fidelity" if not supplied

The Printer object checks to see if the client supplied an "ipp-
attribute-fidelity" Operation attribute.  If the attribute is not

                        Expires July 16, 1998

supplied by the client, the IPP object assumes that the value is
'false'.

15.4.2 Check that the Printer object is accepting jobs

If the value of the Printer object's "printer-is-accepting-jobs" is
'false', the Printer object REJECTS the request and RETURNS the
'server-error-not-accepting-jobs' status code.

15.4.3 Validate the values of the Job Template attributes

An IPP object validates the values of all Job Template attribute
supplied by the client.  The IPP object performs the analogous
syntactic validation checks of each Job Template attribute value that
it performs for Operation attributes (see Section 15.3.4.): 15.3.5.):

     a)
       that the length of each value is correct for the attribute
       syntax tag supplied by the client according to Section 4.1.
     b)
       that the attribute syntax tag is correct for that attribute
       according to Sections 4.2 to 4.6,

                        Expires June 19, 1998 4.4,
     c)
       that multiple values are supplied for multi-valued attributes,
       i.e., that are 1setOf  X according to Sections 4.2 to 4.6 4.4

As in Section 15.3.4, 15.3.5, if any of these syntactic checks fail, the IPP
object REJECTS the request and RETURNS the 'client-error-bad-request',
independent of the value of the "ipp-attribute-fidelity".  Since such
an error is most likely to be an error detected by a client developer,
rather than by an end-user, the IPP object NEED NOT return an
indication of which attribute had the error in either the Unsupported
Attributes Group or the Status Message.  The description for each of
these syntactic checks is explicitly expressed in the first IF
statement in the following table.

In addition, the IPP object loops through all the client-supplied Job
Template attributes, checking to see if the supplied attribute
value(s) are supported or in the range supported, i.e., the value of
the "xxx" attribute in the request is (1) a member of the set of
values or is in the range of values of the Printer' objects "xxx-
supported" attribute.  If the value of the Printer object's "xxx-
supported" attribute is 'no-value' (because the system administrator
hasn't configured a value), the check always fails.  If the check
fails, the IPP object copies the attribute to the Unsupported
Attributes response group with its unsupported value.  If the
attribute contains more than one value, each value is checked and each
unsupported value is separately copied, while supported values are not
copied.  If an IPP object doesn't recognize/support a Job Template

                        Expires July 16, 1998

attribute, i.e., there is no corresponding Printer object "xxx-
supported" attribute, the IPP object treats the attribute as an
unknown or unsupported attribute (see the last row in the table
below).

If some Job Template attributes are supported for some document
formats and not for others or the values are different for different
document formats, the IPP object SHOULD take that into account in this
validation using the value of the "document-format" supplied by the
client (or defaulted to the value of the Printer's "document-format-
default" attribute, if not supplied by the client).  For example, if
"number-up" is supported for the 'text/plain' document format, but not
for the 'application/postscript' document format, or if only the '0'
(none) value is supported for 'application/postscript', the check SHOULD
(though it NEED NOT) depend on the value of the "document-
format" "document-format"
operation attribute.  See "document-format" in section
3.2.1.1. 3.2.1.1 and
3.2.5.1.

Note: whether the request is accepted or rejected is determined by the
value of the "ipp-attribute-fidelity" attribute in a subsequent step,
so that all Job Template attribute supplied are examined and all

                        Expires June 19, 1998
unsupported attributes and/or values are copied to the Unsupported
Attributes response group.

-----------------------------------------------
job-priority (integer(1:100))
  IF NOT any single 'integer' value equal to 4 octets, REJECT/RETURN
     'client-error-bad-request'.
  IF NOT supplied by the client, use the value of the Printer
     object's "job-priority-default" attribute at job submission time.
  IF NOT in the range 1 to 100, inclusive, copy the attribute and the
     unsupported value to the Unsupported Attributes response group.
  Map the value to the nearest supported value in the range 1:100 as
     specified by the number of discrete values indicated by the value
     of the Printer's "job-priority-supported" attribute.  See the
     formula in Section 4.2.1.

job-hold-until (type4 keyword | name)
  IF NOT any single 'keyword' or 'name' value less than 256 octets,
     REJECT/RETURN 'client-error-bad-request'.
  IF NOT supplied by the client, use the value of the Printer
     object's "job-hold-until" attribute at job submission time.
  IF NOT in the Printer object's "job-hold-until-supported"
     attribute, copy the attribute and the unsupported value to the
     Unsupported Attributes response group.

job-sheets (type4 keyword | name)
  IF NOT any single 'keyword' or 'name' value less than 256 octets,
     REJECT/RETURN 'client-error-bad-request'.

                        Expires July 16, 1998
  IF NOT in the Printer object's "job-sheets-supported" attribute,
     copy the attribute and the unsupported value to the Unsupported
     Attributes response group.

multiple-document-handling (type2 keyword)
  IF NOT any single 'keyword' value less than 256 octets,
     REJECT/RETURN 'client-error-bad-request'.
  IF NOT in the Printer object's "multiple-document-handling-
     supported" attribute, copy the attribute and the unsupported
     value to the Unsupported Attributes response group.

copies (integer(1:MAX))
  IF NOT any single 'integer' value equal to 4 octets,
  REJECT/RETURN 'client-error-bad-request'.
  IF NOT in range of the Printer object's "copies-supported"
     attribute
  copy the attribute and the unsupported value to the Unsupported
     Attributes response group.

finishings (1setOf type2 enum)

                        Expires June 19, 1998
  IF NOT any 'keyword' or 'name' value(s) each less than 256 octets,
     REJECT/RETURN 'client-error-bad-request'.
  IF NOT in the Printer object's "finishings-supported" attribute,
     copy the attribute and the unsupported value(s), but not any
     supported values, to the Unsupported Attributes response group.

page-ranges (1setOf  rangeOfInteger(1:MAX))
  IF NOT any 'rangeOfInteger' value(s) each equal to 8 octets,
     REJECT/RETURN 'client-error-bad-request'.
  IF first value is greater than second value in any range, the
     ranges are not in ascending order, or ranges overlap,
     REJECT/RETURN 'client-error-bad-request'.
  IF the value of the Printer object's "page-ranges-supported"
     attribute is 'false', copy the attribute to the Unsupported
     Attributes response group and set the value to the out-of-band "out-of-band"
     'unsupported' value.

sides (type2 keyword)
  IF NOT any single 'keyword' value less than 256 octets,
     REJECT/RETURN 'client-error-bad-request'.
  IF NOT in the Printer object's "sides-supported" attribute, copy
     the attribute and the unsupported value to the Unsupported
     Attributes response group.

number-up (integer(0:MAX)) (integer(1:MAX))
  IF NOT any single 'integer' value equal to 4 octets,
  REJECT/RETURN 'client-error-bad-request'.

                        Expires July 16, 1998
  IF NOT a value or in the range of one of the values of the Printer
     object's "number-up" "number-up-supported" attribute, copy the attribute and
     value to the Unsupported Attribute response group.

orientation

Orientation-requested (type2 enum)
  IF NOT any single 'enum' value equal to 4 octets,
  REJECT/RETURN 'client-error-bad-request'.
  IF NOT in the Printer object's "orientation-supported" "orientation-requested-supported"
     attribute, copy the attribute and the unsupported value to the
     Unsupported Attributes response group.

media (type4 keyword | name)
  IF NOT any single 'keyword' or 'name' value less than 256 octets,
     REJECT/RETURN 'client-error-bad-request'.
  IF NOT in the Printer object's "media-supported" attribute, copy
     the attribute and the unsupported value to the Unsupported
     Attributes response group.

printer-resolution (resolution)
  IF NOT any single 'resolution' value equal to 9 octets,
  REJECT/RETURN 'client-error-bad-request'.

                        Expires June 19, 1998
  IF NOT in the Printer object's "multiple-document-handling-
     supported" attribute, copy the attribute and the unsupported
     value to the Unsupported Attributes response group.

print-quality (type2 enum)
  IF NOT any single 'enum' value equal to 4 octets,
  REJECT/RETURN 'client-error-bad-request'.
  IF NOT in the Printer object's "print-quality-supported" attribute,
     copy the attribute and the unsupported value to the Unsupported
     Attributes response group.

unknown or unsupported attribute (i.e., there is no corresponding
Printer object "xxx-supported" attribute)
  IF the attribute syntax supplied by the client is supported but the
     length is not legal for that attribute syntax,
  REJECT/RETURN 'client-error-bad-request'.
  ELSE copy the attribute and value to the Unsupported Attributes
     response group and change the attribute value to the out-of-band "out-of-
     band" 'unsupported' value.  Any remaining Job Template Attributes
     are either unknown or unsupported Job Template attributes and are
     validated algorithmically according to their attribute syntax for
     proper length (see below).
-----------------------------------------------

If the attribute syntax is supported AND the length check fails, the
IPP object REJECTS the request and RETURNS the 'client-error-bad-
request' status code, else the IPP object copies the unsupported Job

                        Expires July 16, 1998

Template attribute to the Unsupported Attributes response group and
changes the attribute value to the out-of-band "out-of-band" 'unsupported' value.
The following table shows the length checks for all attribute
syntaxes.  In the following table:  "<=" means less than or equal, "="
means equal to:

                        Expires June 19, 1998

Name              Octet length check for read-write attributes
-----------       --------------------------------------------
'text'                <= 1023
'name'                <= 255
'keyword'             <= 255
'keyword'|'name'      <= 255
'enum'                = 4
'uri'                 <= 1023
'uriScheme'           <= 63
'charset'             <= 63
'naturalLanguage'     <= 63
'mimeMediaType'       <= 63
'octetString'         <= 1023
'boolean'             = 1
'integer'             = 4
'rangeOfInteger'      = 8
'dateTime'            = 11
'resolution'          = 9
'1setOf  X'

15.4.3

15.4.4 Check for conflicting Job Template attributes values

Once all the Operation and Job Template attributes have been checked
individually, the Printer object SHOULD check for any conflicting
values among all the supported values supplied by the client.  For
example, a Printer object might be able to staple and to print on
transparencies, however due to physical stapling constraints, the
Printer object might not be able to staple transparencies. The IPP
object copies the supported attributes and their conflicting attribute
values to the Unsupported Attributes response group.  The Printer
object only copies over those attributes that the Printer object
either ignores or substitutes in order to resolve the conflict, and it
returns the original values which were supplied by the client.  For
example suppose the client supplies "finishings" equals 'staple' and
"media" equals 'transparency', but the Printer object does not support
stapling transparencies.  If the Printer chooses to ignore the
stapling request in order to resolve the conflict, the Printer objects
returns "finishings" equal to 'staple' in the Unsupported Attributes
response group.  If any attributes are multi-valued, only the
conflicting values of the attributes are copied.

                        Expires July 16, 1998

Note: The decisions made to resolve the conflict (if there is a
choice) is implementation dependent.

                        Expires June 19, 1998

15.4.4

15.4.5 Decide whether to REJECT the request

If there were any unsupported Job Template attributes or
unsupported/conflicting Job Template attribute values and the client
supplied the "ipp-attribute-fidelity" attribute with the 'true' value,
the Printer object REJECTS the request and return the status code:

  (1) 'client-error-conflicting-attributes' status code, if there
     were any conflicts between attributes supplied by the client.
  (2) 'client-error-attributes-or-values-not-supported' status code,
     otherwise.

Note:  Unsupported Operation attributes or values that are returned do
not affect the status returned in this step.  If the unsupported
Operation attribute was a serious error, the above already rejected
the request in a previous step.  If control gets to this step with
unsupported Operation attributes being returned, they are not serious
errors.

15.4.5

15.4.6 For the Validate-Job operation, RETURN one of the success
status codes

If the requested operation is the Validate-Job operation, the Printer
object returns:

  (1) the "successful-ok" status code, if there are no unsupported or
     conflicting Job Template attributes or values.
  (2) the "successful-ok-conflicting-attributes, if there are any
     conflicting Job Template attribute or values.
  (3) the "successful-ok-ignored-or-substituted-attributes, if there
     are only unsupported Job Template attributes or values.

Note:  Unsupported Operation attributes or values that are returned do
not affect the status returned in this step.  If the unsupported
Operation attribute was a serious error, the above already rejected
the request in a previous step.  If control gets to this step with
unsupported Operation attributes being returned, they are not serious
errors.

15.4.6

                        Expires July 16, 1998

15.4.7 Create the Job object with attributes to support

If "ipp-attribute-fidelity" is set to 'false' (or it was not supplied
by the client), the Printer object:

                        Expires June 19, 1998

  (1) creates a Job object, assigns a unique value to the job's "job-
     uri" and "job-id" attributes, and initializes all of the job's
     other supported Job Description attributes.
  (2) removes all unsupported attributes from the Job object.
  (3) for each unsupported value, removes either the unsupported
     value or substitutes the unsupported attribute value with some
     supported value.  If an attribute has no values after removing
     unsupported values from it, the attribute is removed from the Job
     object (so that the normal default behavior at job processing
     time will take place for that attribute).
  (4) for each conflicting value, removes either the conflicting
     value or substitutes the conflicting attribute value with some
     other supported value.  If an attribute has no values after
     removing conflicting values from it, the attribute is removed
     from the Job object (so that the normal default behavior at job
     processing time will take place for that attribute).

If there were no attributes or values flagged as unsupported, or the
value of 'ipp-attribute-fidelity" was 'false', the Printer object is
able to accept the create request and create a new Job object.  If the
"ipp-attribute-fidelity" attribute is set to 'true', the Job Template
attributes that populate the new Job object are necessarily all the
Job Template attributes supplied in the create request.  If the "ipp-
attribute-fidelity" attribute is set to 'false', the Job Template
attributes that populate the new Job object are all the client
supplied Job Template attributes that are supported or that have value
substitution.  Thus, some of the requested Job Template attributes may
not appear in the Job object because the Printer object did not
support those attributes.  The attributes that populate the Job object
are persistently stored with the Job object for that Job.  A Get-Job-
Attributes operation on that Job object will return only those
attributes that are persistently stored with the Job object.

Note: All Job Template attributes that are persistently stored with
the Job object are intended to be "override values"; that is, they
that take precedence over whatever other embedded instructions might
be in the document data itself.  However, it is not possible for all
Printer objects to realize the semantics of "override".  End users may
query the Printer's "pdl-override" "pdl-override-supported" attribute to determine if
the Printer either attempts or does not attempt to override document
data instructions with IPP attributes.

                        Expires July 16, 1998

There are some cases, where a Printer supports a Job Template
attribute and has an associated default value set for that attribute.
In the case where a client does not supply the corresponding
attribute, the Printer does not use its default values to populate Job
attributes when creating the new Job object; only Job Template
attributes actually in the create request are used to populate the Job

                        Expires June 19, 1998
object. The Printer's default values are only used later at Job
processing time if no other IPP attribute or instruction embedded in
the document data is present.

Note: If the default values associated with Job Template attributes
that the client did not supply were to be used to populate the Job
object, then these values would become "override values" rather than
defaults. If the Printer supports the 'attempted' value of the "pdl-
override"
override-supported" attribute, then these override values could
replace values specified within the document data.  This is not the
intent of the default value mechanism. A default value for an
attribute is used only if the create request did not specify that
attribute (or it was ignored when allowed by "ipp-attribute-fidelity"
being 'false') and no value was provided within the content of the
document data.

If the client does not supply a value for some Job Template attribute,
and the Printer does not support that attribute, as far as IPP is
concerned, the result of processing that Job (with respect to the
missing attribute) is undefined.

15.4.7

15.4.8 Return one of the success status codes

Once the Job object has been created, the Printer object accepts the
request and returns to the client:

  (1) the 'successful-ok' status code, if there are no unsupported or
     conflicting Job Template attributes or values.
  (2) the 'successful-ok-conflicting-attributes' status code, if
     there are any conflicting Job Template attribute or values.
  (3) the 'successful-ok-ignored-or-substituted-attributes' status
     code, if there are only unsupported Job Template attributes or
     values.

Note:  Unsupported Operation attributes or values that are returned do
not affect the status returned in this step.  If the unsupported
Operation attribute was a serious error, the above already rejected
the request in a previous step.  If control gets to this step with
unsupported Operation attributes being returned, they are not serious
errors.

                        Expires July 16, 1998

The Printer object also returns Job status attributes that indicate
the initial state of the Job ('pending', 'pending-held', 'processing',
etc.), etc.  See Print-Job Response, section 3.2.1.2.

                        Expires June 19, 1998

15.4.8

15.4.9 Accept appended Document Content

The Printer object accepts the appended Document Content data and
either starts it printing, or spools it for later processing.

15.4.9

15.4.10 Scheduling and Starting to Process the Job

The Printer object uses its own configuration and implementation
specific algorithms for scheduling the Job in the correct processing
order.  Once the Printer object begins processing the Job, the Printer
changes the Job's state to 'processing'. If the Printer object
supports PDL override (the "pdl-override" "pdl-override-supported" attribute set to
'attempted'), the implementation does its best to see that IPP
attributes take precedence over embedded instructions in the document
data.

15.4.10

15.4.11 Completing the Job

The Printer object continues to process the Job until it can move the
Job into the 'completed' state.  If an Cancel-Job operation is
received, the implementation eventually moves the Job into the
'canceled' state.  If the system encounters errors during processing
that do not allow it to progress the Job into a completed state, the
implementation halts all processing, cleans up any resources, and
moves the Job into the 'aborted' state.

15.4.11

15.4.12 Destroying the Job after completion

Once the Job moves to the 'completed', 'aborted', or 'canceled' state,
it is an implementation decision as to when to destroy the Job object
and release all associated resources.  Once the Job has been
destroyed, the Printer would return either the "client-error-not-
found" or "client-error-gone" status codes for operations directed at
that Job.

Note:  the Printer object SHOULD NOT re-use a "job-uri" or "job-id"
value for a sufficiently long time after a job has been destroyed, so
that stale references kept by clients are less likely to access the
wrong (newer) job.

15.4.12

                        Expires July 16, 1998

15.4.13 Interaction with "ipp-attribute-fidelity"

Some Printer object implementations may support "ipp-attribute-
fidelity" set to 'true' and "pdl-override" "pdl-override-supported" set to
'attempted' and yet

                        Expires June 19, 1998 still not be able to realize exactly what the
client specifies in the create request.  This is due to legacy
decisions and assumptions that have been made about the role of job
instructions embedded within the document data and external job
instructions that accompany the document data and how to handle
conflicts between such instructions.  The inability to be 100% precise
about how a given implementation will behave is also compounded by the
fact that the two special attributes, "ipp-attribute-fidelity" and "pdl-override",
"pdl-override-supported", apply to the whole job rather than specific
values for each attribute. For example, some implementations may be
able to override almost all Job Template attributes except for
"number-up".

15.5 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",
"number-up", "sides", "media", and "copies".  The processing of each
document in a Job Object SHALL 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.

  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 SHALL be formatted. The formatting
     detection algorithm is implementation defined and is not
     specified by this specification. The formatting of the document
     data uses the "orientation" "orientation-requested" attribute to determine how
     the formatted print data is should be placed on a print-stream page,
     see section 4.2.15 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-range" "page-ranges" attribute is used to select, as
     specified in section 4.2.14, 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 value of

                        Expires July 16, 1998
     "number-up" is N, then during the processing of the print-stream
     pages, each N print-stream pages are positioned, as specified in
     section 4.2.8, 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"

                        Expires June 19, 1998
     attribute as described in section 4.2.6; 4.2.4; when the value of this
     attribute is 'single-document', 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 4.2.10 4.2.12
     and 4.2.11. 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 4.2.9. 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
     4.2.6.
     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 4.2.6 4.2.5 and 4.2.13 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 4.2.12. 4.2.6. Note that sometimes
     finishing operations may require manual intervention to perform
     the finishing operations on the copies, especially uncollated
     copies. This specification allows any or all of the processing
     steps to be performed automatically or manually at the discretion
     of the Printer object.

                        Expires July 16, 1998

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

                        Expires June 19, 1998
Printers can be registered (either automatically or with the help of
an administrator) as entries of type printer in the directory.  IPP
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 MANDATORY or OPTIONAL for the directory entry
itself.  This conformance labeling is NOT the same conformance
labeling applied to the attributes of IPP Printers themselves. objects.  MANDATORY
attributes MUST be associated with each directory entry.  OPTIONAL
attributes SHOULD 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.

In order to bridge between the directory service protocol and IPP, the IPP Printer
object, one of the MANDATORY directory entry attributes is the "printer-uri" Printer
object's "printer-uri-supported" attribute.  The IPP client addresses an IPP Printer using its URI and so the directory
entry's "printer-uri" becomes queries
the link between "printer-uri-supported" attribute in the directory entry and then
addresses the corresponding IPP Printer. 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                      (see note below) PRINTER:

  printer-uri-supported            MANDATORY      Section 4.4.1
  printer-tls-uri                  (see note below)
  uri-security-supported           MANDATORY      Section 4.4.2
       Note: Both "printer-uri" and "printer-tls-uri" are allowed
          in a directory entry, but at least one of "printer-uri" or
          "printer-tls-uri" is MANDATORY
  printer-name                     OPTIONAL       Section 4.4.3

                        Expires July 16, 1998
  printer-location                 OPTIONAL       Section 4.4.4
  printer-info                     OPTIONAL       Section 4.4.5
  printer-more-info                OPTIONAL       Section 4.4.6
  printer-make-and-model           OPTIONAL       Section 4.4.8

                        Expires June 19, 1998
  document-format-supported        OPTIONAL       Section 4.4.19
  color-supported                  OPTIONAL       Section 4.4.23
  finishings-supported             OPTIONAL       Section 4.2.6
  number-up-supported              OPTIONAL       Section 4.2.7
  sides-supported                  OPTIONAL       Section 4.2.8
  media-supported                  OPTIONAL       Section 4.2.11
  printer-resolution-supported     OPTIONAL       Section 4.2.12
  print-quality-supported          OPTIONAL       Section 4.2.13
  document-format-supported        OPTIONAL       Section 4.4.19

                        Expires June 19, July 16, 1998