[Docs] [txt|pdf] [Tracker] [WG] [Email] [Diff1] [Diff2] [Nits]

Versions: (RFC 2518) 00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 RFC 4918

WebDAV                                                      L. Dusseault
Internet-Draft                                                      OSAF
Expires: May 19, 2006                                  November 15, 2005


     HTTP Extensions for Distributed Authoring - WebDAV RFC2518 bis
                    draft-ietf-webdav-rfc2518bis-08

Status of this Memo

   By submitting this Internet-Draft, each author represents that any
   applicable patent or other IPR claims of which he or she is aware
   have been or will be disclosed, and any of which he or she becomes
   aware will be disclosed, in accordance with Section 6 of BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF), its areas, and its working groups.  Note that
   other groups may also distribute working documents as Internet-
   Drafts.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   The list of current Internet-Drafts can be accessed at
   http://www.ietf.org/ietf/1id-abstracts.txt.

   The list of Internet-Draft Shadow Directories can be accessed at
   http://www.ietf.org/shadow.html.

   This Internet-Draft will expire on May 19, 2006.

Copyright Notice

   Copyright (C) The Internet Society (2005).

Abstract

   WebDAV consists of a set of methods, headers, and content-types
   ancillary to HTTP/1.1 for the management of resource properties,
   creation and management of resource collections, namespace
   manipulation, and resource locking (collision avoidance).

   RFC2518 was published in February 1998, and this draft makes minor
   revisions mostly due to interoperability experience.





Dusseault                 Expires May 19, 2006                  [Page 1]

Internet-Draft                 RFC2518bis                  November 2005


Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   7
   2.  Notational Conventions  . . . . . . . . . . . . . . . . . . .   9
   3.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .  10
   4.  Data Model for Resource Properties  . . . . . . . . . . . . .  11
     4.1.   The Resource Property Model  . . . . . . . . . . . . . .  11
     4.2.   Properties and HTTP Headers  . . . . . . . . . . . . . .  11
     4.3.   XML Usage  . . . . . . . . . . . . . . . . . . . . . . .  11
     4.4.   Property Values  . . . . . . . . . . . . . . . . . . . .  12
     4.5.   Property Names . . . . . . . . . . . . . . . . . . . . .  13
     4.6.   Source Resources and Output Resources  . . . . . . . . .  13
   5.  Collections of Web Resources  . . . . . . . . . . . . . . . .  15
     5.1.   HTTP URL Namespace Model . . . . . . . . . . . . . . . .  15
     5.2.   Collection Resources . . . . . . . . . . . . . . . . . .  15
   6.  Locking . . . . . . . . . . . . . . . . . . . . . . . . . . .  17
     6.1.   Exclusive Vs. Shared Locks . . . . . . . . . . . . . . .  17
     6.2.   Required Support . . . . . . . . . . . . . . . . . . . .  18
     6.3.   Lock Tokens  . . . . . . . . . . . . . . . . . . . . . .  18
     6.4.   Lock Capability Discovery  . . . . . . . . . . . . . . .  19
     6.5.   Active Lock Discovery  . . . . . . . . . . . . . . . . .  19
     6.6.   Locks and Multiple Bindings  . . . . . . . . . . . . . .  19
   7.  Write Lock  . . . . . . . . . . . . . . . . . . . . . . . . .  21
     7.1.   Lock Owner . . . . . . . . . . . . . . . . . . . . . . .  21
     7.2.   Methods Restricted by Write Locks  . . . . . . . . . . .  21
     7.3.   Write Locks and Lock Tokens  . . . . . . . . . . . . . .  22
     7.4.   Write Locks and Properties . . . . . . . . . . . . . . .  22
     7.5.   Avoiding Lost Updates  . . . . . . . . . . . . . . . . .  22
     7.6.   Write Locks and Unmapped URLs  . . . . . . . . . . . . .  23
     7.7.   Write Locks and Collections  . . . . . . . . . . . . . .  25
     7.8.   Write Locks and the If Request Header  . . . . . . . . .  26
     7.9.   Write Locks and COPY/MOVE  . . . . . . . . . . . . . . .  27
     7.10.  Refreshing Write Locks . . . . . . . . . . . . . . . . .  28
   8.  HTTP Methods for Distributed Authoring  . . . . . . . . . . .  29
     8.1.   General request and response handling  . . . . . . . . .  29
       8.1.1.   Use of XML . . . . . . . . . . . . . . . . . . . . .  29
       8.1.2.   Required Bodies in Requests  . . . . . . . . . . . .  29
       8.1.3.   HTTP Headers for use in WebDAV . . . . . . . . . . .  29
       8.1.4.   ETag . . . . . . . . . . . . . . . . . . . . . . . .  29
       8.1.5.   Including error response bodies  . . . . . . . . . .  30
     8.2.   PROPFIND . . . . . . . . . . . . . . . . . . . . . . . .  31
       8.2.1.   PROPFIND status codes  . . . . . . . . . . . . . . .  32
       8.2.2.   Status codes for use with 207 (Multi-Status) . . . .  33
       8.2.3.   Example - Retrieving Named Properties  . . . . . . .  33
       8.2.4.   Example - Retrieving Named and Dead Properties . . .  34
       8.2.5.   Example - Using propname to Retrieve all Property
                Names  . . . . . . . . . . . . . . . . . . . . . . .  35
     8.3.   PROPPATCH  . . . . . . . . . . . . . . . . . . . . . . .  36



Dusseault                 Expires May 19, 2006                  [Page 2]

Internet-Draft                 RFC2518bis                  November 2005


       8.3.1.   Status Codes for use with 207 (Multi-Status) . . . .  37
       8.3.2.   Example - PROPPATCH  . . . . . . . . . . . . . . . .  38
     8.4.   MKCOL Method . . . . . . . . . . . . . . . . . . . . . .  39
       8.4.1.   MKCOL Status Codes . . . . . . . . . . . . . . . . .  39
       8.4.2.   Example - MKCOL  . . . . . . . . . . . . . . . . . .  40
     8.5.   GET, HEAD for Collections  . . . . . . . . . . . . . . .  40
     8.6.   POST for Collections . . . . . . . . . . . . . . . . . .  41
     8.7.   DELETE . . . . . . . . . . . . . . . . . . . . . . . . .  41
       8.7.1.   DELETE for Non-Collection Resources  . . . . . . . .  41
       8.7.2.   DELETE for Collections . . . . . . . . . . . . . . .  41
       8.7.3.   Example - DELETE . . . . . . . . . . . . . . . . . .  42
     8.8.   PUT  . . . . . . . . . . . . . . . . . . . . . . . . . .  42
       8.8.1.   PUT for Non-Collection Resources . . . . . . . . . .  42
       8.8.2.   PUT for Collections  . . . . . . . . . . . . . . . .  43
     8.9.   COPY . . . . . . . . . . . . . . . . . . . . . . . . . .  43
       8.9.1.   COPY for Non-collection Resources  . . . . . . . . .  43
       8.9.2.   COPY for Properties  . . . . . . . . . . . . . . . .  44
       8.9.3.   COPY for Collections . . . . . . . . . . . . . . . .  44
       8.9.4.   COPY and the Overwrite Header  . . . . . . . . . . .  45
       8.9.5.   Status Codes . . . . . . . . . . . . . . . . . . . .  46
       8.9.6.   COPY Examples  . . . . . . . . . . . . . . . . . . .  46
     8.10.  MOVE . . . . . . . . . . . . . . . . . . . . . . . . . .  48
       8.10.1.  MOVE for Properties  . . . . . . . . . . . . . . . .  49
       8.10.2.  MOVE for Collections . . . . . . . . . . . . . . . .  49
       8.10.3.  MOVE and the Overwrite Header  . . . . . . . . . . .  50
       8.10.4.  Status Codes . . . . . . . . . . . . . . . . . . . .  50
       8.10.5.  Examples . . . . . . . . . . . . . . . . . . . . . .  51
     8.11.  LOCK Method  . . . . . . . . . . . . . . . . . . . . . .  52
       8.11.1.  Refreshing Locks . . . . . . . . . . . . . . . . . .  53
       8.11.2.  Depth and Locking  . . . . . . . . . . . . . . . . .  54
       8.11.3.  Locking Unmapped URLs  . . . . . . . . . . . . . . .  54
       8.11.4.  Lock Compatibility Table . . . . . . . . . . . . . .  54
       8.11.5.  LOCK responses . . . . . . . . . . . . . . . . . . .  55
       8.11.6.  Example - Simple Lock Request  . . . . . . . . . . .  55
       8.11.7.  Example - Refreshing a Write Lock  . . . . . . . . .  58
       8.11.8.  Example - Multi-Resource Lock Request  . . . . . . .  59
     8.12.  UNLOCK Method  . . . . . . . . . . . . . . . . . . . . .  60
       8.12.1.  Status Codes . . . . . . . . . . . . . . . . . . . .  60
       8.12.2.  Example  . . . . . . . . . . . . . . . . . . . . . .  61
   9.  HTTP Headers for Distributed Authoring  . . . . . . . . . . .  62
     9.1.   DAV Header . . . . . . . . . . . . . . . . . . . . . . .  62
     9.2.   Depth Header . . . . . . . . . . . . . . . . . . . . . .  62
     9.3.   Destination Header . . . . . . . . . . . . . . . . . . .  64
     9.4.   Force-Authentication Header  . . . . . . . . . . . . . .  64
     9.5.   If Header  . . . . . . . . . . . . . . . . . . . . . . .  64
       9.5.1.   No-tag-list Production . . . . . . . . . . . . . . .  65
       9.5.2.   Tagged-list Production . . . . . . . . . . . . . . .  66
       9.5.3.   Not Production . . . . . . . . . . . . . . . . . . .  66



Dusseault                 Expires May 19, 2006                  [Page 3]

Internet-Draft                 RFC2518bis                  November 2005


       9.5.4.   Matching Function  . . . . . . . . . . . . . . . . .  67
       9.5.5.   If Header and Non-DAV Aware Proxies  . . . . . . . .  68
     9.6.   Lock-Token Header  . . . . . . . . . . . . . . . . . . .  68
     9.7.   Overwrite Header . . . . . . . . . . . . . . . . . . . .  68
     9.8.   Timeout Request Header . . . . . . . . . . . . . . . . .  69
   10. Status Code Extensions to HTTP/1.1  . . . . . . . . . . . . .  70
     10.1.  102 Processing . . . . . . . . . . . . . . . . . . . . .  70
     10.2.  207 Multi-Status . . . . . . . . . . . . . . . . . . . .  70
     10.3.  422 Unprocessable Entity . . . . . . . . . . . . . . . .  70
     10.4.  423 Locked . . . . . . . . . . . . . . . . . . . . . . .  70
     10.5.  424 Failed Dependency  . . . . . . . . . . . . . . . . .  71
     10.6.  507 Insufficient Storage . . . . . . . . . . . . . . . .  71
   11. Use of HTTP Status Codes  . . . . . . . . . . . . . . . . . .  72
     11.1.  301 Moved Permanently  . . . . . . . . . . . . . . . . .  72
     11.2.  302 Found  . . . . . . . . . . . . . . . . . . . . . . .  72
     11.3.  400 Bad Request  . . . . . . . . . . . . . . . . . . . .  72
     11.4.  403 Forbidden  . . . . . . . . . . . . . . . . . . . . .  72
     11.5.  409 Conflict . . . . . . . . . . . . . . . . . . . . . .  72
     11.6.  412 Precondition Failed  . . . . . . . . . . . . . . . .  72
     11.7.  414 Request-URI Too Long . . . . . . . . . . . . . . . .  73
     11.8.  503 Service Unavailable  . . . . . . . . . . . . . . . .  73
   12. Multi-Status Response . . . . . . . . . . . . . . . . . . . .  74
     12.1.  Response headers . . . . . . . . . . . . . . . . . . . .  74
     12.2.  URL handling . . . . . . . . . . . . . . . . . . . . . .  74
     12.3.  Internal Status Codes  . . . . . . . . . . . . . . . . .  75
   13. XML Element Definitions . . . . . . . . . . . . . . . . . . .  76
     13.1.  activelock XML Element . . . . . . . . . . . . . . . . .  76
     13.2.  depth XML Element  . . . . . . . . . . . . . . . . . . .  76
     13.3.  locktoken XML Element  . . . . . . . . . . . . . . . . .  76
     13.4.  lockroot XML Element . . . . . . . . . . . . . . . . . .  77
     13.5.  timeout XML Element  . . . . . . . . . . . . . . . . . .  77
     13.6.  collection XML Element . . . . . . . . . . . . . . . . .  78
     13.7.  href XML Element . . . . . . . . . . . . . . . . . . . .  78
     13.8.  lockentry XML Element  . . . . . . . . . . . . . . . . .  78
     13.9.  lockinfo XML Element . . . . . . . . . . . . . . . . . .  79
     13.10. lockscope XML Element  . . . . . . . . . . . . . . . . .  79
     13.11. exclusive XML Element  . . . . . . . . . . . . . . . . .  79
     13.12. shared XML Element . . . . . . . . . . . . . . . . . . .  80
     13.13. locktype XML Element . . . . . . . . . . . . . . . . . .  80
     13.14. write XML Element  . . . . . . . . . . . . . . . . . . .  80
     13.15. multistatus XML Element  . . . . . . . . . . . . . . . .  81
     13.16. response XML Element . . . . . . . . . . . . . . . . . .  81
     13.17. propstat XML Element . . . . . . . . . . . . . . . . . .  82
     13.18. status XML Element . . . . . . . . . . . . . . . . . . .  82
     13.19. responsedescription XML Element  . . . . . . . . . . . .  82
     13.20. owner XML Element  . . . . . . . . . . . . . . . . . . .  83
     13.21. prop XML element . . . . . . . . . . . . . . . . . . . .  83
     13.22. propertyupdate XML element . . . . . . . . . . . . . . .  84



Dusseault                 Expires May 19, 2006                  [Page 4]

Internet-Draft                 RFC2518bis                  November 2005


     13.23. remove XML element . . . . . . . . . . . . . . . . . . .  84
     13.24. set XML element  . . . . . . . . . . . . . . . . . . . .  84
     13.25. propfind XML Element . . . . . . . . . . . . . . . . . .  85
     13.26. allprop XML Element  . . . . . . . . . . . . . . . . . .  85
     13.27. propname XML Element . . . . . . . . . . . . . . . . . .  85
     13.28. dead-props XML Element . . . . . . . . . . . . . . . . .  86
     13.29. error XML Element  . . . . . . . . . . . . . . . . . . .  86
   14. DAV Properties  . . . . . . . . . . . . . . . . . . . . . . .  87
     14.1.  creationdate Property  . . . . . . . . . . . . . . . . .  87
     14.2.  displayname Property . . . . . . . . . . . . . . . . . .  88
     14.3.  getcontentlanguage Property  . . . . . . . . . . . . . .  88
     14.4.  getcontentlength Property  . . . . . . . . . . . . . . .  89
     14.5.  getcontenttype Property  . . . . . . . . . . . . . . . .  89
     14.6.  getetag Property . . . . . . . . . . . . . . . . . . . .  90
     14.7.  getlastmodified Property . . . . . . . . . . . . . . . .  91
     14.8.  lockdiscovery Property . . . . . . . . . . . . . . . . .  91
       14.8.1.  Example - Retrieving the lockdiscovery Property  . .  92
     14.9.  resourcetype Property  . . . . . . . . . . . . . . . . .  94
     14.10. supportedlock Property . . . . . . . . . . . . . . . . .  94
       14.10.1. Example - Retrieving the supportedlock Property  . .  96
   15. Precondition/postcondition XML elements . . . . . . . . . . .  97
   16. Instructions for Processing XML in DAV  . . . . . . . . . . . 100
   17. DAV Compliance Classes  . . . . . . . . . . . . . . . . . . . 101
     17.1.  Class 1  . . . . . . . . . . . . . . . . . . . . . . . . 101
     17.2.  Class 2  . . . . . . . . . . . . . . . . . . . . . . . . 101
     17.3.  Class 'bis'  . . . . . . . . . . . . . . . . . . . . . . 101
   18. Internationalization Considerations . . . . . . . . . . . . . 103
   19. Security Considerations . . . . . . . . . . . . . . . . . . . 105
     19.1.  Authentication of Clients  . . . . . . . . . . . . . . . 105
     19.2.  Denial of Service  . . . . . . . . . . . . . . . . . . . 105
     19.3.  Security through Obscurity . . . . . . . . . . . . . . . 106
     19.4.  Privacy Issues Connected to Locks  . . . . . . . . . . . 106
     19.5.  Privacy Issues Connected to Properties . . . . . . . . . 106
     19.6.  Implications of XML External Entities  . . . . . . . . . 107
     19.7.  Risks Connected with Lock Tokens . . . . . . . . . . . . 107
     19.8.  Hosting malicious scripts executed on client machines  . 108
   20. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 109
   21. Acknowledgements  . . . . . . . . . . . . . . . . . . . . . . 110
     21.1.  Previous Authors' Addresses  . . . . . . . . . . . . . . 111
   22. References  . . . . . . . . . . . . . . . . . . . . . . . . . 112
     22.1.  Normative References . . . . . . . . . . . . . . . . . . 112
     22.2.  Informational References . . . . . . . . . . . . . . . . 112
   Appendix A.  Notes on Processing XML Elements . . . . . . . . . . 114
     A.1.   Notes on Empty XML Elements  . . . . . . . . . . . . . . 114
     A.2.   Notes on Illegal XML Processing  . . . . . . . . . . . . 114
     A.3.   Example - XML Syntax Error . . . . . . . . . . . . . . . 114
     A.4.   Example - Unknown XML Element  . . . . . . . . . . . . . 115
   Appendix B.  Notes on HTTP Client Compatibility . . . . . . . . . 116



Dusseault                 Expires May 19, 2006                  [Page 5]

Internet-Draft                 RFC2518bis                  November 2005


   Appendix C.  The opaquelocktoken scheme and URIs  . . . . . . . . 117
   Appendix D.  Changes  . . . . . . . . . . . . . . . . . . . . . . 118
     D.1.   Summary of changes from RFC2518  . . . . . . . . . . . . 118
       D.1.1.   Changes Notable to Server Implementors . . . . . . . 118
       D.1.2.   Changes Notable to Client Implementors . . . . . . . 119
     D.2.   Changes from -05 to -06  . . . . . . . . . . . . . . . . 119
     D.3.   Changes in -07 . . . . . . . . . . . . . . . . . . . . . 120
     D.4.   Changes in -08 . . . . . . . . . . . . . . . . . . . . . 121
   Author's Address  . . . . . . . . . . . . . . . . . . . . . . . . 122
   Intellectual Property and Copyright Statements  . . . . . . . . . 123









































Dusseault                 Expires May 19, 2006                  [Page 6]

Internet-Draft                 RFC2518bis                  November 2005


1.  Introduction

   This document describes an extension to the HTTP/1.1 protocol that
   allows clients to perform remote web content authoring operations.
   This extension provides a coherent set of methods, headers, request
   entity body formats, and response entity body formats that provide
   operations for:

   Properties: The ability to create, remove, and query information
   about Web pages, such as their authors, creation dates, etc.  Also,
   the ability to link pages of any media type to related pages.

   Collections: The ability to create sets of documents and to retrieve
   a hierarchical membership listing (like a directory listing in a file
   system).

   Locking: The ability to keep more than one person from working on a
   document at the same time.  This prevents the "lost update problem",
   in which modifications are lost as first one author then another
   writes changes without merging the other author's changes.

   Namespace Operations: The ability to instruct the server to copy and
   move Web resources.

   Requirements and rationale for these operations are described in a
   companion document, "Requirements for a Distributed Authoring and
   Versioning Protocol for the World Wide Web" (RFC2291) [12].

   This standard does not specify the versioning operations suggested by
   RFC2291 [12].  That work was done in a separate document, "Versioning
   Extensions to WebDAV" (RFC3253) [14].

   The sections below provide a detailed introduction to resource
   properties (Section 4), collections of resources (Section 5), and
   locking operations (Section 6).  These sections introduce the
   abstractions manipulated by the WebDAV-specific HTTP methods
   (Section 8) and the new HTTP headers used with WebDAV methods
   (Section 9).

   While the status codes provided by HTTP/1.1 are sufficient to
   describe most error conditions encountered by WebDAV methods, there
   are some errors that do not fall neatly into the existing categories.
   This specification defines new status codes developed for WebDAV
   methods (Section 10) and describes existing HTTP status codes
   (Section 11) as used in WebDAV.  Since some WebDAV methods may
   operate over many resources, the Multi-Status response (Section 12)
   has been introduced to return status information for multiple
   resources.  Finally, this version of WebDAV introduces XML elements



Dusseault                 Expires May 19, 2006                  [Page 7]

Internet-Draft                 RFC2518bis                  November 2005


   in error response bodies in Section 15.

   WebDAV uses XML [11] to marshal complicated request and response
   information, as well as to express metadata, so this specification
   contains definitions of all XML elements used (Section 13).  WebDAV
   includes a few special rules on how to process XML (Section 16)
   appearing in WebDAV so that it truly is extensible.

   Finishing off the specification are sections on what it means for a
   resource to be compliant with this specification (Section 17), on
   internationalization support (Section 18), and on security
   (Section 19).







































Dusseault                 Expires May 19, 2006                  [Page 8]

Internet-Draft                 RFC2518bis                  November 2005


2.  Notational Conventions

   Since this document describes a set of extensions to the HTTP/1.1
   protocol, the augmented BNF used herein to describe protocol elements
   is exactly the same as described in section 2.1 of RFC2616 [6],
   including the rules about implied linear white-space.  Since this
   augmented BNF uses the basic production rules provided in section 2.2
   of RFC2616 [6], these rules apply to this document as well.

   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 RFC2119 [2].

   Note that in natural language, a property like the "creationdate"
   property in the "DAV:" namespace is sometimes referred to as "DAV:
   creationdate" for brevity.



































Dusseault                 Expires May 19, 2006                  [Page 9]

Internet-Draft                 RFC2518bis                  November 2005


3.  Terminology

   URI/URL - A Uniform Resource Identifier and Uniform Resource Locator,
   respectively.  These terms (and the distinction between them) are
   defined in RFC3986 [8].

   Collection - A resource that contains a set of URLs, which identify
   and locate member resources and which meet the collections
   requirements (Section 5).

   Member URL - A URL which is a member of the set of URLs contained by
   a collection.

   Internal Member URL - A Member URL that is immediately relative to
   the URL of the collection (the definition of immediately relative is
   given later (Section 5.2)).

   Property - A name/value pair that contains descriptive information
   about a resource.

   Live Property - A property whose semantics and syntax are enforced by
   the server.  For example, the live "getcontentlength" property has
   its value, the length of the entity returned by a GET request,
   automatically calculated by the server.

   Dead Property - A property whose semantics and syntax are not
   enforced by the server.  The server only records the value of a dead
   property; the client is responsible for maintaining the consistency
   of the syntax and semantics of a dead property.

   Principal - A "principal" is a distinct human or computational actor
   that initiates access to network resources.



















Dusseault                 Expires May 19, 2006                 [Page 10]

Internet-Draft                 RFC2518bis                  November 2005


4.  Data Model for Resource Properties

4.1.  The Resource Property Model

   Properties are pieces of data that describe the state of a resource.
   Properties are data about data.

   Properties are used in distributed authoring environments to provide
   for efficient discovery and management of resources.  For example, a
   'subject' property might allow for the indexing of all resources by
   their subject, and an 'author' property might allow for the discovery
   of what authors have written which documents.

   The DAV property model consists of name/value pairs.  The name of a
   property identifies the property's syntax and semantics, and provides
   an address by which to refer to its syntax and semantics.

   There are two categories of properties: "live" and "dead".  A live
   property has its syntax and semantics enforced by the server.  Live
   properties include cases where a) the value of a property is read-
   only, maintained by the server, and b) the value of the property is
   maintained by the client, but the server performs syntax checking on
   submitted values.  All instances of a given live property MUST comply
   with the definition associated with that property name.  A dead
   property has its syntax and semantics enforced by the client; the
   server merely records the value of the property verbatim.

4.2.  Properties and HTTP Headers

   Properties already exist, in a limited sense, in HTTP message
   headers.  However, in distributed authoring environments a relatively
   large number of properties are needed to describe the state of a
   resource, and setting/returning them all through HTTP headers is
   inefficient.  Thus a mechanism is needed which allows a principal to
   identify a set of properties in which the principal is interested and
   to set or retrieve just those properties.

4.3.  XML Usage

   In HTTP/1.1, method parameter information was exclusively encoded in
   HTTP headers.  Unlike HTTP/1.1, WebDAV encodes method parameter
   information either in an XML [11] request entity body, or in an HTTP
   header.  The use of XML to encode method parameters was motivated by
   the ability to add extra XML elements to existing structures,
   providing extensibility; and by XML's ability to encode information
   in ISO 10646 character sets, providing internationalization support.

   In addition to encoding method parameters, XML is used in WebDAV to



Dusseault                 Expires May 19, 2006                 [Page 11]

Internet-Draft                 RFC2518bis                  November 2005


   encode the responses from methods, providing the extensibility and
   internationalization advantages of XML for method output, as well as
   input.

   The XML namespace extension [10] is also used in this specification
   in order to allow for new XML elements to be added without fear of
   colliding with other element names.  Although WebDAV request and
   response bodies can be extended by arbitrary XML elements, which can
   be ignored by the message recipient, an XML element in the "DAV:"
   namespace SHOULD NOT be used in the request or response body unless
   that XML element is explicitly defined in an IETF RFC reviewed by a
   WebDAV working group.

   Note that "DAV:" uses a scheme name defined solely for the purpose of
   creating this namespace.  Defining new schemes for namespaces is
   discouraged.  "DAV:" was defined before standard best practices
   emerged, and this namespace is still used only because of significant
   existing deployments.

4.4.  Property Values

   The value of a property is always a (well-formed) XML fragment.

   XML has been chosen because it is a flexible, self-describing,
   structured data format that supports rich schema definitions, and
   because of its support for multiple character sets.  XML's self-
   describing nature allows any property's value to be extended by
   adding new elements.  Older clients will not break when they
   encounter extensions because they will still have the data specified
   in the original schema and will ignore elements they do not
   understand.  XML's support for multiple character sets allows any
   human-readable property to be encoded and read in a character set
   familiar to the user.  XML's support for multiple human languages,
   using the "xml:lang" attribute, handles cases where the same
   character set is employed by multiple human languages.  Note that
   xml:lang scope is recursive, so a xml:lang attribute on any element
   containing a property name element applies to the property value
   unless it has been overridden by a more locally scoped attribute.

   A property is always represented in XML with an XML element
   consisting of the property name.  The simplest example is an empty
   property, which is different from a property that does not exist.

   <R:title xmlns:R="http://www.example.com/ns/"></R:title>

   The value of a property appears inside the property name element.
   The value may be any kind of well-formed XML content, including both
   text-only and mixed content.  When the property value contains



Dusseault                 Expires May 19, 2006                 [Page 12]

Internet-Draft                 RFC2518bis                  November 2005


   further XML elements, namespace names that are in scope for that part
   of the XML document apply within the property value as well, and MUST
   be preserved in server storage for retransmission later.  Namespace
   prefixes need not be preserved due to the rules of prefix declaration
   in XML.

   Attributes on the property name element may convey information about
   the property, but are not considered part of the value.  However,
   when language information appears in the 'xml:lang' attribute on the
   property name element, the language information MUST be preserved in
   server storage for retransmission later.  Note that a property only
   has one value, in one language (or language MAY be left undefined),
   not multiple values in different languages or a single value in
   multiple languages.

   The XML attribute xml:space MUST NOT be used to change white space
   handling.  White space in property values is significant.

4.5.  Property Names

   A property name is a universally unique identifier that is associated
   with a schema that provides information about the syntax and
   semantics of the property.

   Because a property's name is universally unique, clients can depend
   upon consistent behavior for a particular property across multiple
   resources, on the same and across different servers, so long as that
   property is "live" on the resources in question, and the
   implementation of the live property is faithful to its definition.

   The XML namespace mechanism, which is based on URIs [8], is used to
   name properties because it prevents namespace collisions and provides
   for varying degrees of administrative control.

   The property namespace is flat; that is, no hierarchy of properties
   is explicitly recognized.  Thus, if a property A and a property A/B
   exist on a resource, there is no recognition of any relationship
   between the two properties.  It is expected that a separate
   specification will eventually be produced which will address issues
   relating to hierarchical properties.

   Finally, it is not possible to define the same property twice on a
   single resource, as this would cause a collision in the resource's
   property namespace.

4.6.  Source Resources and Output Resources

   Some HTTP resources are dynamically generated by the server.  For



Dusseault                 Expires May 19, 2006                 [Page 13]

Internet-Draft                 RFC2518bis                  November 2005


   these resources, there presumably exists source code somewhere
   governing how that resource is generated.  The relationship of source
   files to output HTTP resources may be one to one, one to many, many
   to one or many to many.  There is no mechanism in HTTP to determine
   whether a resource is even dynamic, let alone where its source files
   exist or how to author them.  Although this problem would usefully be
   solved, interoperable WebDAV implementations have been widely
   deployed without actually solving this problem, by dealing only with
   static resources.  Thus, the source vs. output problem is not solved
   in this specification and has been deferred to a separate document.









































Dusseault                 Expires May 19, 2006                 [Page 14]

Internet-Draft                 RFC2518bis                  November 2005


5.  Collections of Web Resources

   This section provides a description of a new type of Web resource,
   the collection, and discusses its interactions with the HTTP URL
   namespace.  The purpose of a collection resource is to model
   collection-like objects (e.g., file system directories) within a
   server's namespace.

   All DAV compliant resources MUST support the HTTP URL namespace model
   specified herein.

5.1.  HTTP URL Namespace Model

   The HTTP URL namespace is a hierarchical namespace where the
   hierarchy is delimited with the "/" character.

   An HTTP URL namespace is said to be consistent if it meets the
   following conditions: for every URL in the HTTP hierarchy there
   exists a collection that contains that URL as an internal member.
   The root, or top-level collection of the namespace under
   consideration is exempt from the previous rule.  The top-level
   collection of the namespace under consideration is not necessarily
   the collection identified by the absolute path '/', it may be
   identified by one or more path segments (e.g. /servlets/webdav/...)

   Neither HTTP/1.1 nor WebDAV require that the entire HTTP URL
   namespace be consistent -- a WebDAV-compatible resource may not have
   a parent collection.  However, certain WebDAV methods are prohibited
   from producing results that cause namespace inconsistencies.

   Although implicit in RFC2616 [6] and RFC3986 [8], any resource,
   including collection resources, MAY be identified by more than one
   URI.  For example, a resource could be identified by multiple HTTP
   URLs.

5.2.  Collection Resources

   A collection is a resource whose state consists of at least a list of
   internal member URLs and a set of properties, but which may have
   additional state such as entity bodies returned by GET.  An internal
   member URL MUST be immediately relative to a base URL of the
   collection.  That is, the internal member URL is equal to a
   containing collection's URL plus an additional segment for non-
   collection resources, or additional segment plus trailing slash "/"
   for collection resources, where segment is defined in section 3.3 of
   RFC3986 [8].

   Any given internal member URL MUST only belong to the collection



Dusseault                 Expires May 19, 2006                 [Page 15]

Internet-Draft                 RFC2518bis                  November 2005


   once, i.e., it is illegal to have multiple instances of the same URL
   in a collection.  Properties defined on collections behave exactly as
   do properties on non-collection resources.

   For all WebDAV compliant resources A and B, identified by URLs U and
   V, for which U is immediately relative to V, B MUST be a collection
   that has U as an internal member URL.  So, if the resource with URL
   http://example.com/bar/blah is WebDAV compliant and if the resource
   with URL http://example.com/bar/ is WebDAV compliant then the
   resource with URL http://example.com/bar/ must be a collection and
   must contain URL http://example.com/bar/blah as an internal member.

   Collection resources MAY list the URLs of non-WebDAV compliant
   children in the HTTP URL namespace hierarchy as internal members but
   are not required to do so.  For example, if the resource with URL
   http://example.com/bar/blah is not WebDAV compliant and the URL
   http://example.com/bar/ identifies a collection then URL
   http://example.com/bar/blah may or may not be an internal member of
   the collection with URL http://example.com/bar/.

   If a WebDAV compliant resource has no WebDAV compliant children in
   the HTTP URL namespace hierarchy then the WebDAV compliant resource
   is not required to be a collection.

   There is a standing convention that when a collection is referred to
   by its name without a trailing slash, the server MAY handle the
   request as if the trailing slash were present.  In this case it
   SHOULD return a Content-Location header in the response, pointing to
   the URL ending with the "/".  For example, if a client invokes a
   method on http://example.com/blah (no trailing slash), the server may
   respond as if the operation were invoked on http://example.com/blah/
   (trailing slash), and should return a Content-Location header with
   the value http://example.com/blah/.  Wherever a server produces a URL
   referring to a collection, the server MUST include the trailing
   slash.  In general clients SHOULD use the "/" form of collection
   names.

   Clients MUST be able to support the case where WebDAV resources are
   contained inside non-WebDAV resources.  For example, if a OPTIONS
   response from "http://example.com/servlet/dav/collection" indicates
   WebDAV support, the client cannot assume that
   "http://example.com/servlet/dav/" or its parent necessarily are
   WebDAV collections.








Dusseault                 Expires May 19, 2006                 [Page 16]

Internet-Draft                 RFC2518bis                  November 2005


6.  Locking

   The ability to lock a resource provides a mechanism for serializing
   access to that resource.  Using a lock, an authoring client can
   provide a reasonable guarantee that another principal will not modify
   a resource while it is being edited.  In this way, a client can
   prevent the "lost update" problem.

   This specification allows locks to vary over two client-specified
   parameters, the number of principals involved (exclusive vs. shared)
   and the type of access to be granted.  This document defines locking
   for only one access type, write.  However, the syntax is extensible,
   and permits the eventual specification of locking for other access
   types.

6.1.  Exclusive Vs. Shared Locks

   The most basic form of lock is an exclusive lock.  Only one exclusive
   lock may exist on any resource, whether it is directly or indirectly
   locked (Section 7.7).  Exclusive locks avoid having to merge results,
   without requiring any coordination other than the methods described
   in this specification.

   However, there are times when the goal of a lock is not to exclude
   others from exercising an access right but rather to provide a
   mechanism for principals to indicate that they intend to exercise
   their access rights.  Shared locks are provided for this case.  A
   shared lock allows multiple principals to receive a lock.  Hence any
   principal with appropriate access can use the lock.

   With shared locks there are two trust sets that affect a resource.
   The first trust set is created by access permissions.  Principals who
   are trusted, for example, may have permission to write to the
   resource.  Among those who have access permission to write to the
   resource, the set of principals who have taken out a shared lock also
   must trust each other, creating a (typically) smaller trust set
   within the access permission write set.

   Starting with every possible principal on the Internet, in most
   situations the vast majority of these principals will not have write
   access to a given resource.  Of the small number who do have write
   access, some principals may decide to guarantee their edits are free
   from overwrite conflicts by using exclusive write locks.  Others may
   decide they trust their collaborators will not overwrite their work
   (the potential set of collaborators being the set of principals who
   have write permission) and use a shared lock, which informs their
   collaborators that a principal may be working on the resource.




Dusseault                 Expires May 19, 2006                 [Page 17]

Internet-Draft                 RFC2518bis                  November 2005


   The WebDAV extensions to HTTP do not need to provide all of the
   communications paths necessary for principals to coordinate their
   activities.  When using shared locks, principals may use any out of
   band communication channel to coordinate their work (e.g., face-to-
   face interaction, written notes, post-it notes on the screen,
   telephone conversation, Email, etc.)  The intent of a shared lock is
   to let collaborators know who else may be working on a resource.

   Shared locks are included because experience from web distributed
   authoring systems has indicated that exclusive locks are often too
   rigid.  An exclusive lock is used to enforce a particular editing
   process: take out an exclusive lock, read the resource, perform
   edits, write the resource, release the lock.  This editing process
   has the problem that locks are not always properly released, for
   example when a program crashes, or when a lock owner leaves without
   unlocking a resource.  While both timeouts and administrative action
   can be used to remove an offending lock, neither mechanism may be
   available when needed; the timeout may be long or the administrator
   may not be available.

6.2.  Required Support

   A WebDAV compliant resource is not required to support locking in any
   form.  If the resource does support locking it may choose to support
   any combination of exclusive and shared locks for any access types.

   The reason for this flexibility is that locking policy strikes to the
   very heart of the resource management and versioning systems employed
   by various storage repositories.  These repositories require control
   over what sort of locking will be made available.  For example, some
   repositories only support shared write locks while others only
   provide support for exclusive write locks while yet others use no
   locking at all.  As each system is sufficiently different to merit
   exclusion of certain locking features, this specification leaves
   locking as the sole axis of negotiation within WebDAV.

6.3.  Lock Tokens

   A lock token is a type of state token, represented as a URI, which
   identifies a particular lock.  Each lock has exactly one unique lock
   token generated by the server.  Clients MUST NOT attempt to interpret
   lock tokens in any way.

   Lock token URIs MUST be unique across all resources for all time.
   This uniqueness constraint allows lock tokens to be submitted across
   resources and servers without fear of confusion.

   When a LOCK operation creates a new lock, the new lock token is



Dusseault                 Expires May 19, 2006                 [Page 18]

Internet-Draft                 RFC2518bis                  November 2005


   returned in the Lock-Token response header defined in Section 9.6,
   and also in the body of the response.

   Submitting a lock token does not confer full privilege to use the
   lock token or modify the locked resource.  Anyone can find out anyone
   else's lock token by performing lock discovery.  Write access and
   other privileges MUST be enforced through normal privilege or
   authentication mechanisms, not based on the slight obscurity of lock
   token values.

   Since lock tokens are unique, a client MAY submit a lock token in an
   If header on a resource other than the one that returned it.

   This specification encourages servers to create UUIDs for lock
   tokens, and to use the URI form defined by A Universally Unique
   Identifier (UUID) URN Namespace [9].  However servers are free to use
   another valid URI so long as it meets the uniqueness requirements.
   For example, a valid lock token might be constructed using the
   "opaquelocktoken" scheme defined in an appendix of this document.

   Example: "urn:uuid:f81d4fae-7dec-11d0-a765-00a0c91e6bf6"

6.4.  Lock Capability Discovery

   Since server lock support is optional, a client trying to lock a
   resource on a server can either try the lock and hope for the best,
   or perform some form of discovery to determine what lock capabilities
   the server supports.  This is known as lock capability discovery.  A
   client can determine what lock types the server supports by
   retrieving the supportedlock property.

   Any DAV compliant resource that supports the LOCK method MUST support
   the supportedlock property.

6.5.  Active Lock Discovery

   If another principal locks a resource that a principal wishes to
   access, it is useful for the second principal to be able to find out
   who the first principal is.  For this purpose the lockdiscovery
   property is provided.  This property lists all outstanding locks,
   describes their type, and where available, provides their lock token.

   Any DAV compliant resource that supports the LOCK method MUST support
   the lockdiscovery property.

6.6.  Locks and Multiple Bindings

   A resource may be made available through more than one URI.  However



Dusseault                 Expires May 19, 2006                 [Page 19]

Internet-Draft                 RFC2518bis                  November 2005


   locks apply to resources, not URIs.  Therefore a LOCK request on a
   resource MUST NOT succeed if can not be honored by all the URIs
   through which the resource is addressable.
















































Dusseault                 Expires May 19, 2006                 [Page 20]

Internet-Draft                 RFC2518bis                  November 2005


7.  Write Lock

   This section describes the semantics specific to the write lock type.
   The write lock is a specific instance of a lock type, and is the only
   lock type described in this specification.

   An exclusive write lock will prevent parallel changes to a resource
   by any principal other than the write lock holder.  In general terms,
   changes affected by write locks include changes to:

   o  the content of the resource

   o  any dead property of the resource

   o  any live property defined to be lockable (all properties defined
      in this specification are lockable)

   o  the direct membership of the resource, if it is a collection

   o  the URL/location of a resource

   The next few sections describe in more specific terms how write locks
   interact with various operations.

7.1.  Lock Owner

   The creator of the lock is the lock owner.  The server MUST restrict
   the usage of the lock token to the lock owner (both for shared and
   exclusive locks -- for multi-user shared lock cases, each
   authenticated principal MUST obtain its own shared lock).

   The server MAY allow privileged users other than the lock owner to
   destroy a lock (for example, the resource owner or an administrator)
   as a special case of lock usage.

   If an anonymous user requests a lock, the server MAY refuse the
   request.

7.2.  Methods Restricted by Write Locks

   A server MUST reject any write request that alters a write-locked
   resource unless a valid lock token is provided.  The write operations
   defined in HTTP and WebDAV are PUT, POST, PROPPATCH, LOCK, UNLOCK,
   MOVE, COPY (for the destination resource), DELETE, and MKCOL.  All
   other HTTP/WebDAV methods, GET in particular, function independently
   of the lock.  A shared write lock prevents the same operations,
   however it also allows access by any principal that has a shared
   write lock on the same resource.



Dusseault                 Expires May 19, 2006                 [Page 21]

Internet-Draft                 RFC2518bis                  November 2005


   Note, however, that as new methods are created it will be necessary
   to specify how they interact with a write lock.

7.3.  Write Locks and Lock Tokens

   A successful request for an exclusive or shared write lock MUST
   result in the generation of a unique lock token associated with the
   requesting principal.  Thus if five principals have a shared write
   lock on the same resource there will be five lock tokens, one for
   each principal.

7.4.  Write Locks and Properties

   While those without a write lock may not alter a property on a
   resource it is still possible for the values of live properties to
   change, even while locked, due to the requirements of their schemas.
   Only dead properties and live properties defined to respect locks are
   guaranteed not to change while write locked.

7.5.  Avoiding Lost Updates

   Although the write locks provide some help in preventing lost
   updates, they cannot guarantee that updates will never be lost.
   Consider the following scenario:

   Two clients A and B are interested in editing the resource
   'index.html'.  Client A is an HTTP client rather than a WebDAV
   client, and so does not know how to perform locking.

   Client A doesn't lock the document, but does a GET and begins
   editing.

   Client B does LOCK, performs a GET and begins editing.

   Client B finishes editing, performs a PUT, then an UNLOCK.

   Client A performs a PUT, overwriting and losing all of B's changes.

   There are several reasons why the WebDAV protocol itself cannot
   prevent this situation.  First, it cannot force all clients to use
   locking because it must be compatible with HTTP clients that do not
   comprehend locking.  Second, it cannot require servers to support
   locking because of the variety of repository implementations, some of
   which rely on reservations and merging rather than on locking.
   Finally, being stateless, it cannot enforce a sequence of operations
   like LOCK / GET / PUT / UNLOCK.

   WebDAV servers that support locking can reduce the likelihood that



Dusseault                 Expires May 19, 2006                 [Page 22]

Internet-Draft                 RFC2518bis                  November 2005


   clients will accidentally overwrite each other's changes by requiring
   clients to lock resources before modifying them.  Such servers would
   effectively prevent HTTP 1.0 and HTTP 1.1 clients from modifying
   resources.

   WebDAV clients can be good citizens by using a lock / retrieve /
   write /unlock sequence of operations (at least by default) whenever
   they interact with a WebDAV server that supports locking.

   HTTP 1.1 clients can be good citizens, avoiding overwriting other
   clients' changes, by using entity tags in If-Match headers with any
   requests that would modify resources.

   Information managers may attempt to prevent overwrites by
   implementing client-side procedures requiring locking before
   modifying WebDAV resources.

7.6.  Write Locks and Unmapped URLs

   It is possible to lock an unmapped URL in order to lock the name for
   use.  This is a simple way to avoid the lost-update problem on the
   creation of a new resource (another way is to use If-None-Match
   header specified in HTTP 1.1).  It has the side benefit of locking
   the new resource immediately for use of the creator.

   The lost-update problem is not an issue for collections because MKCOL
   can only be used to create a collection, not to overwrite an existing
   collection.  When trying to lock a collection upon creation, clients
   may attempt to increase the likelihood of this by pipelining the
   MKCOL and LOCK requests together (but because this doesn't convert
   two separate operations into one atomic operation there's no
   guarantee this will work).

   A lock request to an unmapped URL SHOULD result in the creation of an
   locked resource with empty content.  A subsequent PUT request with
   the correct lock token SHOULD normally succeed, and this new request
   provides the content, content-type, content-language and other
   information as appropriate.

   In this situation, a WebDAV server that was implemented from RFC2518
   MAY create "lock-null" resources which are special and unusual
   resources.  Historically, a lock-null resource:

   o  Responds with a 404 or 405 to any DAV method except for PUT,
      MKCOL, OPTIONS, PROPFIND, LOCK, UNLOCK.

   o  Appears as a member of its parent collection.




Dusseault                 Expires May 19, 2006                 [Page 23]

Internet-Draft                 RFC2518bis                  November 2005


   o  Disappears (URI becomes unmapped) if its lock goes away before it
      is converted to a regular resource.  (This must also happen if it
      is renamed or moved, or if any parent collection is renamed or
      moved, because locks are tied to URLs).

   o  May be turned into a regular resource when a PUT request to the
      URL is successful.  Ceases to be a lock-null resource.

   o  May be turned into a collection when a MKCOL request to the URL is
      successful.  Ceases to be a lock-null resource.

   o  Has defined values for lockdiscovery and supportedlock properties.

   However, interoperability and compliance problems have been found
   with lock-null resources.  Therefore, they are deprecated.  WebDAV
   servers SHOULD create regular locked empty resources, which are and
   behave in every way as normal resources.  A locked empty resource:

   o  Can be read, deleted, moved, copied, and in all ways behave as a
      regular resource, not a lock-null resource.

   o  Appears as a member of its parent collection.

   o  SHOULD NOT disappear when its lock goes away (clients must
      therefore be responsible for cleaning up their own mess, as with
      any other operation)

   o  SHOULD default to having no content type.

   o  MAY NOT have values for properties like getcontentlanguage which
      haven't been specified yet by the client.

   o  May have content added with a PUT request.  MUST be able to change
      content type.

   o  MUST NOT be turned into a collection.  A MKCOL request must fail
      as it would to any existing resource.

   o  MUST have defined values for lockdiscovery and supportedlock
      properties.

   o  The response MUST indicate that a resource was created, by use of
      the "201 Created" response code (a LOCK request to an existing
      resource instead will result in 200 OK).  The body must still
      include the lockdiscovery property, as with a LOCK request to an
      existing resource.

   The client is expected to update the locked empty resource shortly



Dusseault                 Expires May 19, 2006                 [Page 24]

Internet-Draft                 RFC2518bis                  November 2005


   after locking it, using PUT and possibly PROPPATCH.  When the client
   uses PUT to overwrite a locked empty resource the client MUST supply
   a Content-Type if any is known.  If the client supplies a Content-
   Type value the server MUST set that value (this requirement actually
   applies to any resource that is overwritten but is particularly
   necessary for locked empty resources which are initially created with
   no Content-Type.

   Clients can easily interoperate both with servers that support the
   deprecated lock-null resources and servers that support simpler
   locked empty resources by only attempting PUT after a LOCK to an
   unmapped URL, not MKCOL or GET.

7.7.  Write Locks and Collections

   A write lock on a collection, whether created by a "Depth: 0" or
   "Depth: infinity" lock request, prevents the addition or removal of
   member URLs of the collection by non-lock owners.

   A zero-depth lock on a collection affects changes to the direct
   membership of that collection.  When a principal issues a write
   request to create a new resource in a write locked collection, or
   isses a DELETE, MOVE or other request that would remove an existing
   internal member URL of a write locked collection or change the
   binding name, this request MUST fail if the principal does not
   provide the correct lock token for the locked collection.

   This means that if a collection is locked (depth 0 or infinity), its
   lock-token is required in all these cases:

   o  DELETE a collection's direct internal member

   o  MOVE a member out of the collection

   o  MOVE a member into the collection, unless it overwrites a pre-
      existing member

   o  MOVE to rename it within a collection,

   o  COPY a member into a collection, unless it overwrites a pre-
      existing member

   o  PUT or MKCOL request which would create a new member.

   The collection's lock token is required in addition to the lock token
   on the internal member itself, if it is locked separately.

   In addition, a depth-infinity lock affects all write operations to



Dusseault                 Expires May 19, 2006                 [Page 25]

Internet-Draft                 RFC2518bis                  November 2005


   all descendents of the locked collection.  With a depth-infinity
   lock, the root of the lock is directly locked, and all its
   descendants are indirectly locked.

   o  Any new resource added as a descendent of a depth-infinity locked
      collection becomes indirectly locked.

   o  Any indirectly locked resource moved out of the locked collection
      into an unlocked collection is thereafter unlocked.

   o  Any indirectly locked resource moved out of a locked source
      collection into a depth-infinity locked target collection remains
      indirectly locked but is now within the scope of the lock on the
      target collection (the target collection's lock token will
      thereafter be required to make further changes).

   If a depth-infinity write LOCK request is issued to a collection
   containing member URLs identifying resources that are currently
   locked in a manner which conflicts with the write lock, the request
   MUST fail with a 423 (Locked) status code, and the response SHOULD
   contain the 'missing-lock-token' precondition.

   If a lock owner causes the URL of a resource to be added as an
   internal member URL of a depth-infinity locked collection then the
   new resource MUST be automatically added to the lock.  This is the
   only mechanism that allows a resource to be added to a write lock.
   Thus, for example, if the collection /a/b/ is write locked and the
   resource /c is moved to /a/b/c then resource /a/b/c will be added to
   the write lock.

7.8.  Write Locks and the If Request Header

   If a user agent is not required to have knowledge about a lock when
   requesting an operation on a locked resource, the following scenario
   might occur.  Program A, run by User A, takes out a write lock on a
   resource.  Program B, also run by User A, has no knowledge of the
   lock taken out by Program A, yet performs a PUT to the locked
   resource.  In this scenario, the PUT succeeds because locks are
   associated with a principal, not a program, and thus program B,
   because it is acting with principal A's credential, is allowed to
   perform the PUT.  However, had program B known about the lock, it
   would not have overwritten the resource, preferring instead to
   present a dialog box describing the conflict to the user.  Due to
   this scenario, a mechanism is needed to prevent different programs
   from accidentally ignoring locks taken out by other programs with the
   same authorization.

   In order to prevent these collisions a lock token MUST be submitted



Dusseault                 Expires May 19, 2006                 [Page 26]

Internet-Draft                 RFC2518bis                  November 2005


   by an authorized principal for all locked resources that a method may
   change or the method MUST fail.  A lock token is submitted when it
   appears in an If header.  For example, if a resource is to be moved
   and both the source and destination are locked then two lock tokens
   must be submitted in the if header, one for the source and the other
   for the destination.

   Example - Write Lock


      >>Request

        COPY /~fielding/index.html HTTP/1.1
        Host: www.ics.uci.edu
        Destination: http://www.ics.uci.edu/users/f/fielding/index.html
        If: <http://www.ics.uci.edu/users/f/fielding/index.html>
            (<urn:uuid:f81d4fae-7dec-11d0-a765-00a0c91e6bf6>)


      >>Response

        HTTP/1.1 204 No Content


   In this example, even though both the source and destination are
   locked, only one lock token must be submitted, for the lock on the
   destination.  This is because the source resource is not modified by
   a COPY, and hence unaffected by the write lock.  In this example,
   user agent authentication has previously occurred via a mechanism
   outside the scope of the HTTP protocol, in the underlying transport
   layer.

7.9.  Write Locks and COPY/MOVE

   A COPY method invocation MUST NOT duplicate any write locks active on
   the source.  However, as previously noted, if the COPY copies the
   resource into a collection that is locked with "Depth: infinity",
   then the resource will be added to the lock.

   A successful MOVE request on a write locked resource MUST NOT move
   the write lock with the resource.  However, the resource is subject
   to being added to an existing lock at the destination (see
   Section 7.7).  For example, if the MOVE makes the resource a child of
   a collection that is locked with "Depth: infinity", then the resource
   will be added to that collection's lock.  Additionally, if a resource
   locked with "Depth: infinity" is moved to a destination that is
   within the scope of the same lock (e.g., within the namespace tree
   covered by the lock), the moved resource will again be a added to the



Dusseault                 Expires May 19, 2006                 [Page 27]

Internet-Draft                 RFC2518bis                  November 2005


   lock.  In both these examples, as specified in Section 7.8, an If
   header must be submitted containing a lock token for both the source
   and destination.

7.10.  Refreshing Write Locks

   A client MUST NOT submit the same write lock request twice.  Note
   that a client is always aware it is resubmitting the same lock
   request because it must include the lock token in the If header in
   order to make the request for a resource that is already locked.

   However, a client may submit a LOCK method with an If header but
   without a body.  This form of LOCK MUST only be used to "refresh" a
   lock.  Meaning, at minimum, that any timers associated with the lock
   MUST be re-set.

   A server may return a Timeout header with a lock refresh that is
   different than the Timeout header returned when the lock was
   originally requested.  Additionally clients may submit Timeout
   headers of arbitrary value with their lock refresh requests.
   Servers, as always, may ignore Timeout headers submitted by the
   client.  Note that timeout is measured in seconds remaining until
   expiration.

   If an error is received in response to a refresh LOCK request the
   client MUST NOT assume that the lock was refreshed.

























Dusseault                 Expires May 19, 2006                 [Page 28]

Internet-Draft                 RFC2518bis                  November 2005


8.  HTTP Methods for Distributed Authoring

8.1.  General request and response handling

8.1.1.  Use of XML

   Some of the following new HTTP methods use XML as a request and
   response format.  All DAV compliant clients and resources MUST use
   XML parsers that are compliant with XML [11] and XML Namespaces [10].
   All XML used in either requests or responses MUST be, at minimum,
   well formed and use namespaces correctly.  If a server receives non-
   wellformed XML in a request it MUST reject the entire request with a
   400 (Bad Request).  If a client receives ill-formed XML in a response
   then it MUST NOT assume anything about the outcome of the executed
   method and SHOULD treat the server as malfunctioning.

8.1.2.  Required Bodies in Requests

   Some of these new methods do not define bodies.  Servers MUST examine
   all requests for a body, even when a body was not expected.  In cases
   where a request body is present but would be ignored by a server, the
   server MUST reject the request with 415 (Unsupported Media Type).
   This informs the client (which may have been attempting to use an
   extension) that the body could not be processed as they intended.

8.1.3.  HTTP Headers for use in WebDAV

   HTTP defines many headers that can be used in WebDAV requests and
   responses.  Not all of these are appropriate in all situations and
   some interactions may be undefined.  Note that HTTP 1.1 requires the
   Date header in all responses if possible.

8.1.4.  ETag

   HTTP 1.1 recommends the use of the ETag header in responses to GET
   and PUT requests.  Correct use of ETags is even more important in a
   distributed authoring environment, because ETags are necessary along
   with locks to avoid the lost-update problem.  A client might fail to
   renew a lock, for example when the lock times out and the client is
   accidentally offline or in the middle of a long upload.  When a
   client fails to renew the lock, it's quite possible the resource can
   still be relocked and the user can go on editing, as long as no
   changes were made in the meantime.  ETags are required for the client
   to be able to distinguish this case.  Otherwise, the client is forced
   to ask the user whether to overwrite the resource on the server
   without even being able to tell the user whether it has changed.
   Timestamps do not solve this problem nearly as well as ETags.




Dusseault                 Expires May 19, 2006                 [Page 29]

Internet-Draft                 RFC2518bis                  November 2005


   WebDAV servers SHOULD support strong ETags for all resources that may
   be PUT.  If ETags are supported for a resource, the server MUST
   return the ETag header in all PUT and GET responses to that resource,
   as well as provide the same value for the 'getetag' property.

   Because clients may be forced to prompt users or throw away changed
   content if the ETag changes, a WebDAV server SHOULD NOT change the
   ETag (or getlastmodified value) for a resource that has an unchanged
   body.  The ETag represents the state of the body or contents of the
   resource.  There is no similar way to tell if properties have
   changed.

8.1.5.  Including error response bodies

   HTTP and WebDAV did not use the bodies of most error responses for
   machine-parsable information until DeltaV introduced a mechanism to
   include more specific information in the body of an error response
   (section 1.6 of RFC3253 [14]).  The mechanism is appropriate to use
   with any error response that may take a body but does not already
   have a body defined.  The mechanism is particularly appropriate when
   a status code can mean many things (for example, 400 Bad Request can
   mean required headers are missing, headers are incorrectly formatted,
   or much more).

   This mechanism does not take the place of using a correct numeric
   error code as defined here or in HTTP, because the client MUST always
   be able to take a reasonable course of action based only on the
   numeric error.  However, it does remove the need to define new
   numeric error codes, avoiding the confusion of who is allowed to
   define such new codes.  The codes used in this mechanism are XML
   elements in a namespace, so naturally any group defining a new error
   code can use their own namespace.  As always, the "DAV:" namespace is
   reserved for use by IETF-chartered WebDAV working groups.

   A server supporting "bis" SHOULD include a specific XML error code in
   a "DAV:error" response body element, when a specific XML error code
   is defined in this document.  The DAV:error element may contain
   multiple elements describing specific errors.  For error conditions
   not specified in this document, the server MAY simply choose an
   appropriate numeric status and leave the response body blank.

        HTTP/1.1 403 Forbidden
        Content-Type: text/xml; charset="utf-8"
        Content-Length: xxxx

        <?xml version="1.0" encoding="utf-8" ?>
        <D:error xmlns:D="DAV:">
          <D:forbid-external-entities/>



Dusseault                 Expires May 19, 2006                 [Page 30]

Internet-Draft                 RFC2518bis                  November 2005


        </D:error>

   In this specification, both the numeric and the XML error code are
   defined for some failure situations, in which case the XML error code
   must have the "DAV:" namespace, appear in the "error" root element,
   and be returned in a body with the numeric error code specified.

8.2.  PROPFIND

   The PROPFIND method retrieves properties defined on the resource
   identified by the Request-URI, if the resource does not have any
   internal members, or on the resource identified by the Request-URI
   and potentially its member resources, if the resource is a collection
   that has internal member URLs.  All DAV compliant resources MUST
   support the PROPFIND method and the propfind XML element
   (Section 13.25) along with all XML elements defined for use with that
   element.

   A client may submit a Depth header with a value of "0", "1", or
   "infinity" with a PROPFIND on a collection resource.  Servers MUST
   support the "0", "1" and "infinity" behaviors on WebDAV-compliant
   resources.  By default, the PROPFIND method without a Depth header
   MUST act as if a "Depth: infinity" header was included.

   A client may submit a propfind XML element in the body of the request
   method describing what information is being requested.  It is
   possible to:

   o  Request particular property values, by naming the properties
      desired within the 'prop' element (the ordering of properties in
      here MAY be ignored by server)

   o  Request all dead property values, by using 'dead-props' element.
      This can be combined with retrieving specific live properties
      named as above.  Servers advertising support for RFC2518bis MUST
      support this feature.

   o  Request property values for those properties defined in this
      specification plus dead properties, by using 'allprop' element

   o  Request a list of names of all the properties defined on the
      resource, by using the 'propname' element.

   A client may choose not to submit a request body.  An empty PROPFIND
   request body MUST be treated as if it were an 'allprop' request.

   Note that 'allprop' does not return values for all live properties.
   WebDAV servers increasingly have expensively-calculated or lengthy



Dusseault                 Expires May 19, 2006                 [Page 31]

Internet-Draft                 RFC2518bis                  November 2005


   properties (see RFC3253 [14] and RFC3744 [15]) and do not return all
   properties already.  Instead, WebDAV clients can use propname
   requests to discover what live properties exist, and request named
   properties when retrieving values.  A WebDAV server MAY omit certain
   live properties from other specifications when responding to an
   allprop request from an older client, and MAY return only custom
   (dead) properties and those defined in this specification.

   All servers MUST support returning a response of content type text/
   xml or application/xml that contains a multistatus XML element that
   describes the results of the attempts to retrieve the various
   properties.

   If there is an error retrieving a property then a proper error result
   MUST be included in the response.  A request to retrieve the value of
   a property which does not exist is an error and MUST be noted, if the
   response uses a multistatus XML element, with a response XML element
   which contains a 404 (Not Found) status value.

   Consequently, the multistatus XML element for a collection resource
   with member URLs MUST include a response XML element for each member
   URL of the collection, to whatever depth was requested.  Each
   response XML element MUST contain an href XML element that gives the
   URL of the resource on which the properties in the prop XML element
   are defined.  Results for a PROPFIND on a collection resource with
   internal member URLs are returned as a flat list whose order of
   entries is not significant.

   Properties may be subject to access control.  In the case of allprop
   and propname, if a principal does not have the right to know whether
   a particular property exists then the property MAY be silently
   excluded from the response.

   The results of this method SHOULD NOT be cached.

8.2.1.  PROPFIND status codes

   A server MAY fail an entire PROPFIND request with an appropriate
   status code and MAY redirect the entire request.  In addition, the
   following error codes are specifically defined for PROPFIND requests:

   403 Forbidden - A server MAY reject all PROPFIND requests on
   collections with depth header of "Infinity", in which case it SHOULD
   use this error with the element 'propfind-infinite-depth-forbidden'
   inside the error body.






Dusseault                 Expires May 19, 2006                 [Page 32]

Internet-Draft                 RFC2518bis                  November 2005


8.2.2.  Status codes for use with 207 (Multi-Status)

   The following status codes are defined for use within the PROPFIND
   Multi-Status response:

      200 OK - A property exists and/or its value is successfully
      returned.

      401 Unauthorized - The property cannot be viewed without
      appropriate authorization.

      403 Forbidden - The property cannot be viewed regardless of
      authentication.

      404 Not Found - The property does not exist.

8.2.3.  Example - Retrieving Named Properties

    >>Request

      PROPFIND  /file HTTP/1.1
      Host: www.example.com
      Content-type: text/xml; charset="utf-8"
      Content-Length: xxxx

      <?xml version="1.0" encoding="utf-8" ?>
      <D:propfind xmlns:D="DAV:">
       <D:prop xmlns:R="http://www.example.com/boxschema/">
         <R:bigbox/>
         <R:author/>
         <R:DingALing/>
         <R:Random/>
       </D:prop>
      </D:propfind>

    >>Response

      HTTP/1.1 207 Multi-Status
      Content-Type: text/xml; charset="utf-8"
      Content-Length: xxxx

      <?xml version="1.0" encoding="utf-8" ?>
      <D:multistatus xmlns:D="DAV:">
       <D:response xmlns:R="http://www.example.com/boxschema/">
         <D:href>http://www.example.com/file</D:href>
         <D:propstat>
           <D:prop>
             <R:bigbox>



Dusseault                 Expires May 19, 2006                 [Page 33]

Internet-Draft                 RFC2518bis                  November 2005


               <R:BoxType>Box type A</R:BoxType>
             </R:bigbox>
             <R:author>
               <R:Name>J.J. Johnson</R:Name>
             </R:author>
           </D:prop>
           <D:status>HTTP/1.1 200 OK</D:status>
         </D:propstat>
         <D:propstat>
           <D:prop><R:DingALing/><R:Random/></D:prop>
           <D:status>HTTP/1.1 403 Forbidden</D:status>
           <D:responsedescription> The user does not have access to the
      DingALing property.
           </D:responsedescription>
         </D:propstat>
       </D:response>
       <D:responsedescription> There has been an access violation error.
       </D:responsedescription>
      </D:multistatus>

   In this example, PROPFIND is executed on a non-collection resource
   http://www.example.com/file.  The propfind XML element specifies the
   name of four properties whose values are being requested.  In this
   case only two properties were returned, since the principal issuing
   the request did not have sufficient access rights to see the third
   and fourth properties.

8.2.4.  Example - Retrieving Named and Dead Properties

      >>Request

        PROPFIND /mycol/ HTTP/1.1
        Host: www.example.com
        Depth: 1
        Content-type: text/xml; charset="utf-8"
        Content-Length: xxxx

        <?xml version="1.0" encoding="utf-8" ?>
        <D:propfind xmlns:D="DAV:">
         <D:prop>
           <D:creationdate/>
           <D:getlastmodified/>
         </D:prop>
         <D:dead-props/>
        </D:propfind>

   In this example, PROPFIND is executed on a collection resource
   http://www.example.com/mycol/.  The client requests the values of two



Dusseault                 Expires May 19, 2006                 [Page 34]

Internet-Draft                 RFC2518bis                  November 2005


   specific live properties plus all dead properties (names and values).
   The response is not shown.

8.2.5.  Example - Using propname to Retrieve all Property Names

      >>Request
        PROPFIND  /container/ HTTP/1.1
        Host: www.example.com
        Content-Type: text/xml; charset="utf-8"
        Content-Length: xxxx

        <?xml version="1.0" encoding="utf-8" ?>
        <propfind xmlns="DAV:">
         <propname/>
        </propfind>

      >>Response

        HTTP/1.1 207 Multi-Status
        Content-Type: text/xml; charset="utf-8"
        Content-Length: xxxx

        <?xml version="1.0" encoding="utf-8" ?>
        <multistatus xmlns="DAV:">
         <response>
           <href>http://www.example.com/container/</href>
           <propstat>
             <prop xmlns:R="http://www.example.com/boxschema/">
               <R:bigbox/>
               <R:author/>
               <creationdate/>
               <displayname/>
               <resourcetype/>
               <supportedlock/>
             </prop>
             <status>HTTP/1.1 200 OK</status>
           </propstat>
         </response>
         <response>
           <href>http://www.example.com/container/front.html</href>
           <propstat>
             <prop xmlns:R="http://www.example.com/boxschema/">
               <R:bigbox/>
               <creationdate/>
               <displayname/>
               <getcontentlength/>
               <getcontenttype/>
               <getetag/>



Dusseault                 Expires May 19, 2006                 [Page 35]

Internet-Draft                 RFC2518bis                  November 2005


               <getlastmodified/>
               <resourcetype/>
               <supportedlock/>
             </prop>
             <status>HTTP/1.1 200 OK</status>
           </propstat>
         </response>
        </multistatus>

   In this example, PROPFIND is invoked on the collection resource
   http://www.example.com/container/, with a propfind XML element
   containing the propname XML element, meaning the name of all
   properties should be returned.  Since no Depth header is present, it
   assumes its default value of "infinity", meaning the name of the
   properties on the collection and all its descendents should be
   returned.

   Consistent with the previous example, resource
   http://www.example.com/container/ has six properties defined on it:
   bigbox and author in the "http://www.example.com/boxschema/"
   namespace, and creationdate, displayname, resourcetype, and
   supportedlock in the "DAV:" namespace.

   The resource http://www.example.com/container/index.html, a member of
   the "container" collection, has nine properties defined on it, bigbox
   in the "http://www.example.com/boxschema/" namespace and,
   creationdate, displayname, getcontentlength, getcontenttype, getetag,
   getlastmodified, resourcetype, and supportedlock in the "DAV:"
   namespace.

   This example also demonstrates the use of XML namespace scoping and
   the default namespace.  Since the "xmlns" attribute does not contain
   a prefix, the namespace applies by default to all enclosed elements.
   Hence, all elements which do not explicitly state the namespace to
   which they belong are members of the "DAV:" namespace.

8.3.  PROPPATCH

   The PROPPATCH method processes instructions specified in the request
   body to set and/or remove properties defined on the resource
   identified by the Request-URI.

   All DAV compliant resources MUST support the PROPPATCH method and
   MUST process instructions that are specified using the
   propertyupdate, set, and remove XML elements.  Execution of the
   directives in this method is, of course, subject to access control
   constraints.  DAV compliant resources SHOULD support the setting of
   arbitrary dead properties.



Dusseault                 Expires May 19, 2006                 [Page 36]

Internet-Draft                 RFC2518bis                  November 2005


   The request message body of a PROPPATCH method MUST contain the
   propertyupdate XML element.  Instruction processing MUST occur in
   document order (an exception to the normal rule that ordering is
   irrelevant).  Instructions MUST either all be executed or none
   executed.  Thus if any error occurs during processing all executed
   instructions MUST be undone and a proper error result returned.
   Instruction processing details can be found in the definition of the
   set and remove instructions in sections 13.23 and section 13.24.

8.3.1.  Status Codes for use with 207 (Multi-Status)

   The following are examples of response codes one would expect to be
   used in a 207 (Multi-Status) response for this method.  Note,
   however, that unless explicitly prohibited any 2/3/4/5xx series
   response code may be used in a 207 (Multi-Status) response.

   200 (OK) - The command succeeded.  As there can be a mixture of sets
   and removes in a body, a 201 (Created) seems inappropriate.

   403 (Forbidden) - The client, for reasons the server chooses not to
   specify, cannot alter one of the properties.

   403 (Forbidden): The client has attempted to set a read- only
   property, such as getetag.  If returning this error, the server
   SHOULD use 'read-only-property' inside the response body.

   409 (Conflict) - The client has provided a value whose semantics are
   not appropriate for the property.

   423 (Locked) - The specified resource is locked and the client either
   is not a lock owner or the lock type requires a lock token to be
   submitted and the client did not submit it.  This response SHOULD
   contain the 'missing-lock-token' precondition element.

   424 (Failed Dependency) - The property change could not be made
   because of another property change that failed.

   507 (Insufficient Storage) - The server did not have sufficient space
   to record the property.












Dusseault                 Expires May 19, 2006                 [Page 37]

Internet-Draft                 RFC2518bis                  November 2005


8.3.2.  Example - PROPPATCH

      >>Request

        PROPPATCH /bar.html HTTP/1.1
        Host: www.example.com
        Content-Type: text/xml; charset="utf-8"
        Content-Length: xxxx

        <?xml version="1.0" encoding="utf-8" ?>
        <D:propertyupdate xmlns:D="DAV:"
        xmlns:Z="http://www.w3.com/standards/z39.50/">
         <D:set>
           <D:prop>
             <Z:authors>
               <Z:Author>Jim Whitehead</Z:Author>
               <Z:Author>Roy Fielding</Z:Author>
             </Z:authors>
           </D:prop>
         </D:set>
         <D:remove>
           <D:prop><Z:Copyright-Owner/></D:prop>
         </D:remove>
        </D:propertyupdate>

      >>Response

        HTTP/1.1 207 Multi-Status
        Content-Type: text/xml; charset="utf-8"
        Content-Length: xxxx

        <?xml version="1.0" encoding="utf-8" ?>
        <D:multistatus xmlns:D="DAV:"
        xmlns:Z="http://www.w3.com/standards/z39.50">
         <D:response>
           <D:href>http://www.example.com/bar.html</D:href>
           <D:propstat>
             <D:prop><Z:Authors/></D:prop>
             <D:status>HTTP/1.1 424 Failed Dependency</D:status>
           </D:propstat>
           <D:propstat>
             <D:prop><Z:Copyright-Owner/></D:prop>
             <D:status>HTTP/1.1 409 Conflict</D:status>
           </D:propstat>
           <D:responsedescription> Copyright Owner can not be deleted or
        altered.</D:responsedescription>
         </D:response>
        </D:multistatus>



Dusseault                 Expires May 19, 2006                 [Page 38]

Internet-Draft                 RFC2518bis                  November 2005


   In this example, the client requests the server to set the value of
   the "Authors" property in the "http://www.w3.com/standards/z39.50/"
   namespace, and to remove the property "Copyright-Owner" in the
   "http://www.w3.com/standards/z39.50/" namespace.  Since the
   Copyright-Owner property could not be removed, no property
   modifications occur.  The 424 (Failed Dependency) status code for the
   Authors property indicates this action would have succeeded if it
   were not for the conflict with removing the Copyright-Owner property.

8.4.  MKCOL Method

   The MKCOL method is used to create a new collection.  All WebDAV
   compliant resources MUST support the MKCOL method.

   MKCOL creates a new collection resource at the location specified by
   the Request-URI.  If the resource identified by the Request-URI is
   non-null then the MKCOL MUST fail.  During MKCOL processing, a server
   MUST make the Request-URI a member of its parent collection, unless
   the Request-URI is "/".  If no such ancestor exists, the method MUST
   fail.  When the MKCOL operation creates a new collection resource,
   all ancestors MUST already exist, or the method MUST fail with a 409
   (Conflict) status code.  For example, if a request to create
   collection /a/b/c/d/ is made, and /a/b/c/ does not exist, the request
   must fail.

   When MKCOL is invoked without a request body, the newly created
   collection SHOULD have no members.

   A MKCOL request message may contain a message body.  The precise
   behavior of a MKCOL request when the body is present is undefined,
   but limited to creating collections, members of a collection, bodies
   of members and properties on the collections or members.  If the
   server receives a MKCOL request entity type it does not support or
   understand it MUST respond with a 415 (Unsupported Media Type) status
   code.  If the server decides to reject the request based on the
   presence of an entity or the type of an entity, it should use the 415
   (Unsupported Media Type) status code.

8.4.1.  MKCOL Status Codes

   Responses from a MKCOL request MUST NOT be cached as MKCOL has non-
   idempotent semantics.

   201 (Created) - The collection was created.

   403 (Forbidden) - This indicates at least one of two conditions: 1)
   the server does not allow the creation of collections at the given
   location in its namespace, or 2) the parent collection of the



Dusseault                 Expires May 19, 2006                 [Page 39]

Internet-Draft                 RFC2518bis                  November 2005


   Request-URI exists but cannot accept members.

   405 (Method Not Allowed) - MKCOL can only be executed on an unmapped
   URL.

   409 (Conflict) - A collection cannot be made at the Request-URI until
   one or more intermediate collections have been created.  The server
   MUST NOT create those intermediate collections automatically.

   415 (Unsupported Media Type) - The server does not support the
   request type of the body.

   507 (Insufficient Storage) - The resource does not have sufficient
   space to record the state of the resource after the execution of this
   method.

8.4.2.  Example - MKCOL

   This example creates a collection called /webdisc/xfiles/ on the
   server www.example.com.

      >>Request

        MKCOL /webdisc/xfiles/ HTTP/1.1
        Host: www.example.com

      >>Response

        HTTP/1.1 201 Created


8.5.  GET, HEAD for Collections

   The semantics of GET are unchanged when applied to a collection,
   since GET is defined as, "retrieve whatever information (in the form
   of an entity) is identified by the Request-URI" [RFC2616].  GET when
   applied to a collection may return the contents of an "index.html"
   resource, a human-readable view of the contents of the collection, or
   something else altogether.  Hence it is possible that the result of a
   GET on a collection will bear no correlation to the membership of the
   collection.

   Similarly, since the definition of HEAD is a GET without a response
   message body, the semantics of HEAD are unmodified when applied to
   collection resources.






Dusseault                 Expires May 19, 2006                 [Page 40]

Internet-Draft                 RFC2518bis                  November 2005


8.6.  POST for Collections

   Since by definition the actual function performed by POST is
   determined by the server and often depends on the particular
   resource, the behavior of POST when applied to collections cannot be
   meaningfully modified because it is largely undefined.  Thus the
   semantics of POST are unmodified when applied to a collection.

8.7.  DELETE

   Locks rooted on a resource MUST be destroyed in a successful DELETE
   of that resource.

8.7.1.  DELETE for Non-Collection Resources

   When a client issues a DELETE request to a Request-URI mapping to a
   non-collection resource, if the operation is successful the server
   MUST remove that mapping.  Thus, after a successful DELETE operation
   (and in the absence of other actions) a subsequent GET/HEAD/PROPFIND
   request to the target Request-URI MUST return 404 (Not Found).

8.7.2.  DELETE for Collections

   The DELETE method on a collection MUST act as if a "Depth: infinity"
   header was used on it.  A client MUST NOT submit a Depth header with
   a DELETE on a collection with any value but infinity.

   DELETE instructs that the collection specified in the Request-URI and
   all resources identified by its internal member URLs are to be
   deleted.

   If any resource identified by a member URL cannot be deleted then all
   of the member's ancestors MUST NOT be deleted, so as to maintain
   namespace consistency.

   Any headers included with DELETE MUST be applied in processing every
   resource to be deleted.

   When the DELETE method has completed processing it MUST result in a
   consistent namespace.

   If an error occurs deleting an internal resource (a resource other
   than the resource identified in the Request-URI) then the response
   can be a 207 (Multi-Status).  Multi-Status is used here to indicate
   which internal resources could NOT be deleted, including an error
   code which should help the client understand which resources caused
   the failure.  For example, the Multi-Status body could include a
   response with status 423 (Locked) if an internal resource was locked.



Dusseault                 Expires May 19, 2006                 [Page 41]

Internet-Draft                 RFC2518bis                  November 2005


   The server MAY return a 4xx status response, rather than a Multi-
   Status, if the request failed.

   424 (Failed Dependency) errors SHOULD NOT be in the 207 (Multi-
   Status) response for DELETE.  They can be safely left out because the
   client will know that the ancestors of a resource could not be
   deleted when the client receives an error for the ancestor's progeny.
   Additionally 204 (No Content) errors SHOULD NOT be returned in the
   207 (Multi- Status).  The reason for this prohibition is that 204 (No
   Content) is the default success code.

8.7.3.  Example - DELETE


      >>Request

        DELETE  /container/ HTTP/1.1
        Host: www.example.com

      >>Response

        HTTP/1.1 207 Multi-Status
        Content-Type: text/xml; charset="utf-8"
        Content-Length: xxxx

        <?xml version="1.0" encoding="utf-8" ?>
        <d:multistatus xmlns:d="DAV:">
         <d:response>
           <d:href>http://www.example.com/container/resource3</d:href>
           <d:status>HTTP/1.1 423 Locked</d:status>
         </d:response>
        </d:multistatus>

   In this example the attempt to delete
   http://www.example.com/container/resource3 failed because it is
   locked, and no lock token was submitted with the request.
   Consequently, the attempt to delete http://www.example.com/container/
   also failed.  Thus the client knows that the attempt to delete
   http://www.example.com/container/ must have also failed since the
   parent can not be deleted unless its child has also been deleted.
   Even though a Depth header has not been included, a depth of infinity
   is assumed because the method is on a collection.

8.8.  PUT

8.8.1.  PUT for Non-Collection Resources

   A PUT performed on an existing resource replaces the GET response



Dusseault                 Expires May 19, 2006                 [Page 42]

Internet-Draft                 RFC2518bis                  November 2005


   entity of the resource.  Properties defined on the resource may be
   recomputed during PUT processing but are not otherwise affected.  For
   example, if a server recognizes the content type of the request body,
   it may be able to automatically extract information that could be
   profitably exposed as properties.

   A PUT that would result in the creation of a resource without an
   appropriately scoped parent collection MUST fail with a 409
   (Conflict).

8.8.2.  PUT for Collections

   As defined in RFC2616 [6], the "PUT method requests that the enclosed
   entity be stored under the supplied Request-URI."  Since submission
   of an entity representing a collection would implicitly encode
   creation and deletion of resources, this specification intentionally
   does not define a transmission format for creating a collection using
   PUT.  Instead, the MKCOL method is defined to create collections.  A
   PUT request to an existing collection MAY be treated as an error (405
   Method Not Allowed).

8.9.  COPY

   The COPY method creates a duplicate of the source resource identified
   by the Request-URI, in the destination resource identified by the URI
   in the Destination header.  The Destination header MUST be present.
   The exact behavior of the COPY method depends on the type of the
   source resource.  The state of the resource to be copied is fixed at
   the point the server begins processing the COPY request.

   All WebDAV compliant resources MUST support the COPY method.
   However, support for the COPY method does not guarantee the ability
   to copy a resource.  For example, separate programs may control
   resources on the same server.  As a result, it may not be possible to
   copy a resource to a location that appears to be on the same server.

8.9.1.  COPY for Non-collection Resources

   When the source resource is not a collection the result of the COPY
   method is the creation of a new resource at the destination whose
   state and behavior match that of the source resource as closely as
   possible.  Since the environment at the destination may be different
   than at the source due to factors outside the scope of control of the
   server, such as the absence of resources required for correct
   operation, it may not be possible to completely duplicate the
   behavior of the resource at the destination.  Subsequent alterations
   to the destination resource will not modify the source resource.
   Subsequent alterations to the source resource will not modify the



Dusseault                 Expires May 19, 2006                 [Page 43]

Internet-Draft                 RFC2518bis                  November 2005


   destination resource.

8.9.2.  COPY for Properties

   After a successful COPY invocation, all dead properties on the source
   resource MUST be duplicated on the destination resource, along with
   all properties as appropriate.  Live properties described in this
   document SHOULD be duplicated as identically behaving live properties
   at the destination resource, but not necessarily with the same
   values.  If a property cannot be copied live, then its value MUST be
   duplicated, octet-for-octet, in an identically named, dead property
   on the destination resource.

   A COPY operation creates a new resource, much like a PUT operation
   does.  Live properties which are related to resource creation (such
   as creationdate) should have their values set accordingly.

8.9.3.  COPY for Collections

   The COPY method on a collection without a Depth header MUST act as if
   a Depth header with value "infinity" was included.  A client may
   submit a Depth header on a COPY on a collection with a value of "0"
   or "infinity".  Servers MUST support the "0" and "infinity" Depth
   header behaviors on WebDAV-compliant resources.

   A COPY of depth infinity instructs that the collection resource
   identified by the Request-URI is to be copied to the location
   identified by the URI in the Destination header, and all its internal
   member resources are to be copied to a location relative to it,
   recursively through all levels of the collection hierarchy.  Servers
   should of course avoid infinite recursion, and can do so by copying
   the source resource as it existed at the point where processing
   started.

   A COPY of "Depth: 0" only instructs that the collection and its
   properties but not resources identified by its internal member URLs,
   are to be copied.

   Any headers included with a COPY MUST be applied in processing every
   resource to be copied with the exception of the Destination header.

   The Destination header only specifies the destination URI for the
   Request-URI.  When applied to members of the collection identified by
   the Request-URI the value of Destination is to be modified to reflect
   the current location in the hierarchy.  So, if the Request-URI is /a/
   with Host header value http://example.com/ and the Destination is
   http://example.com/b/ then when http://example.com/a/c/d is processed
   it must use a Destination of http://example.com/b/c/d.



Dusseault                 Expires May 19, 2006                 [Page 44]

Internet-Draft                 RFC2518bis                  November 2005


   When the COPY method has completed processing it MUST have created a
   consistent namespace at the destination (see Section 8.7.2for the
   definition of namespace consistency).  However, if an error occurs
   while copying an internal collection, the server MUST NOT copy any
   resources identified by members of this collection (i.e., the server
   must skip this subtree), as this would create an inconsistent
   namespace.  After detecting an error, the COPY operation SHOULD try
   to finish as much of the original copy operation as possible (i.e.,
   the server should still attempt to copy other subtrees and their
   members, that are not descendents of an error-causing collection).

   So, for example, if an infinite depth copy operation is performed on
   collection /a/, which contains collections /a/b/ and /a/c/, and an
   error occurs copying /a/b/, an attempt should still be made to copy
   /a/c/.  Similarly, after encountering an error copying a non-
   collection resource as part of an infinite depth copy, the server
   SHOULD try to finish as much of the original copy operation as
   possible.

   If an error in executing the COPY method occurs with a resource other
   than the resource identified in the Request-URI then the response
   MUST be a 207 (Multi-Status), and the URL of the resource causing the
   failure MUST appear with the specific error.

   The 424 (Failed Dependency) status code SHOULD NOT be returned in the
   207 (Multi-Status) response from a COPY method.  These responses can
   be safely omitted because the client will know that the progeny of a
   resource could not be copied when the client receives an error for
   the parent.  Additionally 201 (Created)/204 (No Content) status codes
   SHOULD NOT be returned as values in 207 (Multi-Status) responses from
   COPY methods.  They, too, can be safely omitted because they are the
   default success codes.

8.9.4.  COPY and the Overwrite Header

   If a resource exists at the destination and the Overwrite header is
   "T" then prior to performing the copy the server MUST perform a
   DELETE with "Depth: infinity" on the destination resource.  If the
   Overwrite header is set to "F" then the operation will fail.
   (Extensions to WebDAV might not follow this rule to the letter but
   must consider backwards compatibility with clients that expect COPY
   to work this way.)

   Interoperability testing has shown that some clients expect a
   collection COPY to actually do a merge if a destination collection
   exists.  That behavior is appropriate for file system folders but not
   necessarily for other data objects modelled as collections.  Thus,
   implementors are urged to comply with the standard language above,



Dusseault                 Expires May 19, 2006                 [Page 45]

Internet-Draft                 RFC2518bis                  November 2005


   and leave clients to perform a manual merge if that's the expected
   behavior when copying a collection over another collection.

8.9.5.  Status Codes

   201 (Created) - The source resource was successfully copied.  The
   copy operation resulted in the creation of a new resource.

   204 (No Content) - The source resource was successfully copied to a
   pre-existing destination resource.

   207 (Multi-Status) - Multiple resources were to be affected by the
   COPY, but errors on some of them prevented the operation from taking
   place.  Specific error messages, together with the most appropriate
   of the source and destination URLs, appear in the body of the multi-
   status response.  E.g. if a destination resource was locked and could
   not be overwritten, then the destination resource URL appears with
   the 423 (Locked) status.

   403 (Forbidden) - The operation is forbidden.  Possibly this is
   because the source and destination resources are the same resource.

   409 (Conflict) - A resource cannot be created at the destination
   until one or more intermediate collections have been created.  The
   server MUST NOT create those intermediate collections automatically.

   412 (Precondition Failed) - A precondition failed, e.g. the Overwrite
   header is "F" and the state of the destination resource is non-null.

   423 (Locked) - The destination resource, or resource within the
   destination collection, was locked.  This response SHOULD contain the
   'missing-lock-token' precondition element.

   502 (Bad Gateway) - This may occur when the destination is on another
   server, repository or namespace.  Either the source namespace does
   not support copying to the destination namespace, or the destination
   namespace refuses to accept the resource.  The client may wish to try
   GET/PUT and PROPFIND/PROPPATCH instead.

   507 (Insufficient Storage) - The destination resource does not have
   sufficient space to record the state of the resource after the
   execution of this method.

8.9.6.  COPY Examples

   This example shows resource
   http://www.ics.uci.edu/~fielding/index.html being copied to the
   location http://www.ics.uci.edu/users/f/fielding/index.html.  The 204



Dusseault                 Expires May 19, 2006                 [Page 46]

Internet-Draft                 RFC2518bis                  November 2005


   (No Content) status code indicates the existing resource at the
   destination was overwritten.

   COPY with Overwrite

      >>Request

        COPY /~fielding/index.html HTTP/1.1
        Host: www.ics.uci.edu
        Destination: http://www.ics.uci.edu/users/f/fielding/index.html

      >>Response

        HTTP/1.1 204 No Content

   The following example shows the same copy operation being performed,
   but with the Overwrite header set to "F." A response of 412
   (Precondition Failed) is returned because the destination resource
   has a non-null state.

   COPY with No Overwrite


      >>Request

        COPY /~fielding/index.html HTTP/1.1
        Host: www.ics.uci.edu
        Destination: http://www.ics.uci.edu/users/f/fielding/index.html
        Overwrite: F

      >>Response

        HTTP/1.1 412 Precondition Failed


















Dusseault                 Expires May 19, 2006                 [Page 47]

Internet-Draft                 RFC2518bis                  November 2005


   Example - COPY of a Collection

      >>Request

        COPY /container/ HTTP/1.1
        Host: www.example.com
        Destination: http://www.example.com/othercontainer/
        Depth: infinity

      >>Response

        HTTP/1.1 207 Multi-Status
        Content-Type: text/xml; charset="utf-8"
        Content-Length: xxxx

        <?xml version="1.0" encoding="utf-8" ?>

        <d:multistatus xmlns:d="DAV:">
         <d:response>
           <d:href>http://www.example.com/othercontainer/R2/</d:href>
           <d:status>HTTP/1.1 423 Locked</d:status>
         </d:response>
        </d:multistatus>

   The Depth header is unnecessary as the default behavior of COPY on a
   collection is to act as if a "Depth: infinity" header had been
   submitted.  In this example most of the resources, along with the
   collection, were copied successfully.  However the collection R2
   failed because the destination R2 is locked.  Because there was an
   error copying R2, none of R2's members were copied.  However no
   errors were listed for those members due to the error minimization
   rules.

8.10.  MOVE

   The MOVE operation on a non-collection resource is the logical
   equivalent of a copy (COPY), followed by consistency maintenance
   processing, followed by a delete of the source, where all three
   actions are performed atomically.  The consistency maintenance step
   allows the server to perform updates caused by the move, such as
   updating all URLs other than the Request-URI which identify the
   source resource, to point to the new destination resource.
   Consequently, the Destination header MUST be present on all MOVE
   methods and MUST follow all COPY requirements for the COPY part of
   the MOVE method.  All WebDAV compliant resources MUST support the
   MOVE method.  However, support for the MOVE method does not guarantee
   the ability to move a resource to a particular destination.




Dusseault                 Expires May 19, 2006                 [Page 48]

Internet-Draft                 RFC2518bis                  November 2005


   For example, separate programs may actually control different sets of
   resources on the same server.  Therefore, it may not be possible to
   move a resource within a namespace that appears to belong to the same
   server.

   If a resource exists at the destination, the destination resource
   will be deleted as a side-effect of the MOVE operation, subject to
   the restrictions of the Overwrite header.

8.10.1.  MOVE for Properties

   Live properties described in this document MUST be moved along with
   the resource, such that the resource has identically behaving live
   properties at the destination resource, but not necessarily with the
   same values.  If the live properties will not work the same way at
   the destination, the server MUST fail the request (the client can
   perform COPY then DELETE if it wants a MOVE to work that badly).
   This can mean that the server reports the live property as "Not
   Found" if that's the most appropriate behavior for that live property
   at the destination, as long as the live property is still supported
   with the same semantics.

   MOVE is frequently used by clients to rename a file without changing
   its parent collection, so it's not appropriate to reset live
   properties which are set at resource creation.  For example, the
   creationdate property value SHOULD remain the same after a MOVE.

   Dead properties must be moved along with the resource.

8.10.2.  MOVE for Collections

   A MOVE with "Depth: infinity" instructs that the collection
   identified by the Request-URI be moved to the address specified in
   the Destination header, and all resources identified by its internal
   member URLs are to be moved to locations relative to it, recursively
   through all levels of the collection hierarchy.

   The MOVE method on a collection MUST act as if a "Depth: infinity"
   header was used on it.  A client MUST NOT submit a Depth header on a
   MOVE on a collection with any value but "infinity".

   Any headers included with MOVE MUST be applied in processing every
   resource to be moved with the exception of the Destination header.
   The behavior of the Destination header is the same as given for COPY
   on collections.

   When the MOVE method has completed processing it MUST have created a
   consistent namespace at both the source and destination (see section



Dusseault                 Expires May 19, 2006                 [Page 49]

Internet-Draft                 RFC2518bis                  November 2005


   5.1 for the definition of namespace consistency).  However, if an
   error occurs while moving an internal collection, the server MUST NOT
   move any resources identified by members of the failed collection
   (i.e., the server must skip the error-causing subtree), as this would
   create an inconsistent namespace.  In this case, after detecting the
   error, the move operation SHOULD try to finish as much of the
   original move as possible (i.e., the server should still attempt to
   move other subtrees and the resources identified by their members,
   that are not descendents of an error-causing collection).  So, for
   example, if an infinite depth move is performed on collection /a/,
   which contains collections /a/b/ and /a/c/, and an error occurs
   moving /a/b/, an attempt should still be made to try moving /a/c/.
   Similarly, after encountering an error moving a non- collection
   resource as part of an infinite depth move, the server SHOULD try to
   finish as much of the original move operation as possible.

   If an error occurs with a resource other than the resource identified
   in the Request-URI then the response MUST be a 207 (Multi-Status),
   and the errored resource's URL MUST appear with the specific error.

   The 424 (Failed Dependency) status code SHOULD NOT be returned in the
   207 (Multi-Status) response from a MOVE method.  These errors can be
   safely omitted because the client will know that the progeny of a
   resource could not be moved when the client receives an error for the
   parent.  Additionally 201 (Created)/204 (No Content) responses SHOULD
   NOT be returned as values in 207 (Multi-Status) responses from a
   MOVE.  These responses can be safely omitted because they are the
   default success codes.

8.10.3.  MOVE and the Overwrite Header

   If a resource exists at the destination and the Overwrite header is
   "T" then prior to performing the move the server MUST perform a
   DELETE with "Depth: infinity" on the destination resource.  If the
   Overwrite header is set to "F" then the operation will fail.

8.10.4.  Status Codes

   201 (Created) - The source resource was successfully moved, and a new
   resource was created at the destination.

   204 (No Content) - The source resource was successfully moved to a
   pre-existing destination resource.

   207 (Multi-Status) - Multiple resources were to be affected by the
   MOVE, but errors on some of them prevented the operation from taking
   place.  Specific error messages, together with the most appropriate
   of the source and destination URLs, appear in the body of the multi-



Dusseault                 Expires May 19, 2006                 [Page 50]

Internet-Draft                 RFC2518bis                  November 2005


   status response.  E.g. if a source resource was locked and could not
   be moved, then the source resource URL appears with the 423 (Locked)
   status.

   403 (Forbidden) - The source and destination resources are the same.

   409 (Conflict) - A resource cannot be created at the destination
   until one or more intermediate collections have been created.  The
   server MUST NOT create those intermediate collections automatically.
   Or, the server was unable to preserve the behavior of the live
   properties and still move the resource to the destination (see 'live-
   properties-not-preserved' postcondition).

   412 (Precondition Failed) - A condition failed, e.g. the Overwrite
   header is "F" and the state of the destination resource is non-null.

   423 (Locked) - The source or the destination resource, or some
   resource within the source or destination collection, was locked.
   This response SHOULD contain the 'missing-lock-token' precondition
   element.

   502 (Bad Gateway) - This may occur when the destination is on another
   server and the destination server refuses to accept the resource.
   This could also occur when the destination is on another sub-section
   of the same server namespace.

8.10.5.  Examples

   This example shows resource
   http://www.ics.uci.edu/~fielding/index.html being moved to the
   location http://www.ics.uci.edu/users/f/fielding/index.html.  The
   contents of the destination resource would have been overwritten if
   the destination resource had been non-null.  In this case, since
   there was nothing at the destination resource, the response code is
   201 (Created).

   MOVE of a Non-Collection

      >>Request

        MOVE /~fielding/index.html HTTP/1.1
        Host: www.ics.uci.edu
        Destination: http://www.ics.uci.edu/users/f/fielding/index.html

      >>Response

        HTTP/1.1 201 Created
        Location: http://www.ics.uci.edu/users/f/fielding/index.html



Dusseault                 Expires May 19, 2006                 [Page 51]

Internet-Draft                 RFC2518bis                  November 2005


   MOVE of a Collection

      >>Request

        MOVE /container/ HTTP/1.1
        Host: www.example.com
        Destination: http://www.example.com/othercontainer/
        Overwrite: F
        If: (<urn:uuid:fe184f2e-6eec-41d0-c765-01adc56e6bb4>)
            (<urn:uuid:e454f3f3-acdc-452a-56c7-00a5c91e4b77>)


      >>Response

        HTTP/1.1 207 Multi-Status
        Content-Type: text/xml; charset="utf-8"
        Content-Length: xxxx

        <?xml version="1.0" encoding="utf-8" ?>
        <d:multistatus xmlns:d='DAV:'>
         <d:response>
           <d:href>http://www.example.com/othercontainer/C2/</d:href>
           <d:status>HTTP/1.1 423 Locked</d:status>
         </d:response>
        </d:multistatus>

   In this example the client has submitted a number of lock tokens with
   the request.  A lock token will need to be submitted for every
   resource, both source and destination, anywhere in the scope of the
   method, that is locked.  In this case the proper lock token was not
   submitted for the destination
   http://www.example.com/othercontainer/C2/.  This means that the
   resource /container/C2/ could not be moved.  Because there was an
   error moving /container/C2/, none of /container/C2's members were
   moved.  However no errors were listed for those members due to the
   error minimization rules.  User agent authentication has previously
   occurred via a mechanism outside the scope of the HTTP protocol, in
   an underlying transport layer.

8.11.  LOCK Method

   The following sections describe the LOCK method, which is used to
   take out a lock of any access type and to refresh an existing lock.
   These sections on the LOCK method describe only those semantics that
   are specific to the LOCK method and are independent of the access
   type of the lock being requested.

   Any resource which supports the LOCK method MUST, at minimum, support



Dusseault                 Expires May 19, 2006                 [Page 52]

Internet-Draft                 RFC2518bis                  November 2005


   the XML request and response formats defined herein.

   A LOCK method invocation to an unlocked resource creates a lock on
   the resource identified by the Request-URI, which becomes the root of
   the lock.  Lock method requests to create a new lock MUST have a XML
   request body which contains an owner XML element and other
   information for this lock request.  The server MUST preserve the
   information provided by the client in the owner field when the lock
   information is requested.  The LOCK request MAY have a Timeout
   header.

   Clients MUST assume that locks may arbitrarily disappear at any time,
   regardless of the value given in the Timeout header.  The Timeout
   header only indicates the behavior of the server if extraordinary
   circumstances do not occur.  For example, a sufficiently privileged
   user may remove a lock at any time or the system may crash in such a
   way that it loses the record of the lock's existence.

   When a new lock is created, the LOCK response:

      MUST contain a body with the value of the lockdiscovery property
      in a prop XML element.

      MUST include the Lock-Token response header with the token
      associated with the new lock.

8.11.1.  Refreshing Locks

   A lock is refreshed by sending a LOCK request without a request body
   to the URL of a resource within the scope of the lock.  This request
   MUST specify which lock to refresh by using the 'Lock-Token' header
   with a single lock token (only one lock may be refreshed at a time).
   It MAY contain a Timeout header, which a server MAY accept to change
   the duration remaining on the lock to the new value.  A server MUST
   ignore the Depth header on a LOCK refresh.

   If the resource has other (shared) locks, those locks are unaffected
   by a lock refresh.  Additionally, those locks do not prevent the
   named lock from being refreshed.

   Note that in RFC2518, clients were indicated through the example in
   the text to use the If header to specify what lock to refresh (rather
   than the Lock-Token header).  Servers are encouraged to continue to
   support this as well as the Lock-Token header.

   Note that the Lock-Token header is not be returned in the response
   for a successful refresh LOCK request, but the LOCK response body
   MUST contain the new value for the lockdiscovery body.



Dusseault                 Expires May 19, 2006                 [Page 53]

Internet-Draft                 RFC2518bis                  November 2005


8.11.2.  Depth and Locking

   The Depth header may be used with the LOCK method.  Values other than
   0 or infinity MUST NOT be used with the Depth header on a LOCK
   method.  All resources that support the LOCK method MUST support the
   Depth header.

   A Depth header of value 0 means to just lock the resource specified
   by the Request-URI.

   If the Depth header is set to infinity then the resource specified in
   the Request-URI along with all its internal members, all the way down
   the hierarchy, are to be locked.  A successful result MUST return a
   single lock token which represents all the resources that have been
   locked.  If an UNLOCK is successfully executed on this token, all
   associated resources are unlocked.  If the lock cannot be granted to
   all resources, a 207 (Multi-Status) status code MUST be returned with
   a response entity body containing a multistatus XML element
   describing which resource(s) prevented the lock from being granted.
   Hence, partial success is not an option.  Either the entire hierarchy
   is locked or no resources are locked.

   If no Depth header is submitted on a LOCK request then the request
   MUST act as if a "Depth:infinity" had been submitted.

8.11.3.  Locking Unmapped URLs

   A successful LOCK method MUST result in the creation of an empty
   resource which is locked (and which is not a collection), when a
   resource did not previously exist at that URL.  Later on, the lock
   may go away but the empty resource remains.  Empty resources MUST
   then appear in PROPFIND responses including that URL in the response
   scope.  A server MUST respond successfully to a GET request to an
   empty resource, either by using a 204 No Content response, or by
   using 200 OK with a Content-Length header indicating zero length and
   no Content-Type.

8.11.4.  Lock Compatibility Table

   The table below describes the behavior that occurs when a lock
   request is made on a resource.


        Current State   Shared Lock Request   Exclusive Lock Request
      ----------------------------------------------------------------
        None            True                  True
        Shared Lock     True                  False
        Exclusive Lock  False                 False*



Dusseault                 Expires May 19, 2006                 [Page 54]

Internet-Draft                 RFC2518bis                  November 2005


   Legend: True = lock may be granted.  False = lock MUST NOT be
   granted. *=It is illegal for a principal to request the same lock
   twice.

   The current lock state of a resource is given in the leftmost column,
   and lock requests are listed in the first row.  The intersection of a
   row and column gives the result of a lock request.  For example, if a
   shared lock is held on a resource, and an exclusive lock is
   requested, the table entry is "false", indicating the lock must not
   be granted.

8.11.5.  LOCK responses

   200 (OK) - The lock request succeeded and the value of the
   lockdiscovery property is included in the body.

   409 (Conflict) - A resource cannot be created at the destination
   until one or more intermediate collections have been created.  The
   server MUST NOT create those intermediate collections automatically.

   423 (Locked) - The resource is locked already.  For consistency's
   sake, this response SHOULD contain the 'missing-lock-token'
   precondition element.

   h 400 (Bad Request), with 'request-uri-must-match-lock-token'
   precondition - The LOCK request was made with a Lock-Token header,
   indicating that the client wishes to refresh the given lock.
   However, the Request-URI did not fall within the scope of the lock
   identified by the token.  The lock may have a scope that does not
   include the Request-URI, or the lock could have disappeared, or the
   token may be invalid.

   424 (Failed Dependency) - This may appear inside a 207 response to a
   LOCK request, to indicate that a resource could not be locked because
   of a failure on another resource.

8.11.6.  Example - Simple Lock Request

    >>Request

      LOCK /workspace/webdav/proposal.doc HTTP/1.1
      Host: example.com
      Timeout: Infinite, Second-4100000000
      Content-Type: text/xml; charset="utf-8"
      Content-Length: xxxx
      Authorization: Digest username="ejw",
         realm="ejw@example.com", nonce="...",
         uri="/workspace/webdav/proposal.doc",



Dusseault                 Expires May 19, 2006                 [Page 55]

Internet-Draft                 RFC2518bis                  November 2005


         response="...", opaque="..."

      <?xml version="1.0" encoding="utf-8" ?>
      <D:lockinfo xmlns:D='DAV:'>
       <D:lockscope><D:exclusive/></D:lockscope>
       <D:locktype><D:write/></D:locktype>
       <D:owner>
         <D:href>http://www.ics.uci.edu/~ejw/contact.html</D:href>
       </D:owner>
      </D:lockinfo>

    >>Response

      HTTP/1.1 200 OK
      Lock-Token: <urn:uuid:e71d4fae-5dec-22d6-fea5-00a0c91e6be4>
      Content-Type: text/xml; charset="utf-8"
      Content-Length: xxxx

      <?xml version="1.0" encoding="utf-8" ?>
      <D:prop xmlns:D="DAV:">
       <D:lockdiscovery>
         <D:activelock>
           <D:locktype><D:write/></D:locktype>
           <D:lockscope><D:exclusive/></D:lockscope>
           <D:depth>infinity</D:depth>
           <D:owner>
             <D:href>
               http://www.ics.uci.edu/~ejw/contact.html
             </D:href>
           </D:owner>
           <D:timeout>Second-604800</D:timeout>
           <D:locktoken>
             <D:href>urn:uuid:e71d4fae-5dec-22d6-fea5-00a0c91e6be4<
             /D:href>
           </D:locktoken>
           <D:lockroot>
             <D:href
             >http://example.com/workspace/webdav/proposal.doc<
             /D:href>
           </D:lockroot>
         </D:activelock>
       </D:lockdiscovery>
      </D:prop>


   This example shows the successful creation of an exclusive write lock
   on resource http://example.com/workspace/webdav/proposal.doc.  The
   resource http://www.ics.uci.edu/~ejw/contact.html contains contact



Dusseault                 Expires May 19, 2006                 [Page 56]

Internet-Draft                 RFC2518bis                  November 2005


   information for the owner of the lock.  The server has an activity-
   based timeout policy in place on this resource, which causes the lock
   to automatically be removed after 1 week (604800 seconds).  Note that
   the nonce, response, and opaque fields have not been calculated in
   the Authorization request header.

   Note that the locktoken and lockroot href elements would not contain
   any whitespace.  The line return appearing in this document is only
   for formatting.










































Dusseault                 Expires May 19, 2006                 [Page 57]

Internet-Draft                 RFC2518bis                  November 2005


8.11.7.  Example - Refreshing a Write Lock

    >>Request

      LOCK /workspace/webdav/proposal.doc HTTP/1.1
      Host: example.com
      Timeout: Infinite, Second-4100000000
      Lock-Token: <urn:uuid:e71d4fae-5dec-22d6-fea5-00a0c91e6be4>
      Authorization: Digest username="ejw",
         realm="ejw@example.com", nonce="...",
         uri="/workspace/webdav/proposal.doc",
         response="...", opaque="..."

    >>Response

      HTTP/1.1 200 OK
      Content-Type: text/xml; charset="utf-8"
      Content-Length: xxxx

      <?xml version="1.0" encoding="utf-8" ?>
      <D:prop xmlns:D="DAV:">
       <D:lockdiscovery>
         <D:activelock>
           <D:locktype><D:write/></D:locktype>
           <D:lockscope><D:exclusive/></D:lockscope>
           <D:depth>infinity</D:depth>
           <D:owner>
             <D:href>
             http://www.ics.uci.edu/~ejw/contact.html
             </D:href>
           </D:owner>
           <D:timeout>Second-604800</D:timeout>
           <D:locktoken>
             <D:href>urn:uuid:e71d4fae-5dec-22d6-fea5-00a0c91e6be4<
             /D:href>
           </D:locktoken>
           <D:lockroot>
             <D:href
             >http://example.com/workspace/webdav/proposal.doc<
             /D:href>
           </D:lockroot>
         </D:activelock>
       </D:lockdiscovery>
      </D:prop>


   This request would refresh the lock, attempting to reset the timeout
   to the new value specified in the timeout header.  Notice that the



Dusseault                 Expires May 19, 2006                 [Page 58]

Internet-Draft                 RFC2518bis                  November 2005


   client asked for an infinite time out but the server choose to ignore
   the request.  In this example, the nonce, response, and opaque fields
   have not been calculated in the Authorization request header.

8.11.8.  Example - Multi-Resource Lock Request

      >>Request

        LOCK /webdav/ HTTP/1.1
        Host: example.com
        Timeout: Infinite, Second-4100000000
        Depth: infinity
        Content-Type: text/xml; charset="utf-8"
        Content-Length: xxxx
        Authorization: Digest username="ejw",
           realm="ejw@example.com", nonce="...",
           uri="/workspace/webdav/proposal.doc",
           response="...", opaque="..."

        <?xml version="1.0" encoding="utf-8" ?>
        <D:lockinfo xmlns:D="DAV:">
         <D:locktype><D:write/></D:locktype>
         <D:lockscope><D:exclusive/></D:lockscope>
         <D:owner>
           <D:href>http://www.ics.uci.edu/~ejw/contact.html</D:href>
         </D:owner>
        </D:lockinfo>

      >>Response

        HTTP/1.1 207 Multi-Status
        Content-Type: text/xml; charset="utf-8"
        Content-Length: xxxx

        <?xml version="1.0" encoding="utf-8" ?>
        <D:multistatus xmlns:D="DAV:">
         <D:response>
           <D:href>http://example.com/webdav/secret</D:href>
           <D:status>HTTP/1.1 403 Forbidden</D:status>
         </D:response>
         <D:response>
           <D:href>http://example.com/webdav/</D:href>
           <D:propstat>
             <D:prop><D:lockdiscovery/></D:prop>
             <D:status>HTTP/1.1 424 Failed Dependency</D:status>
           </D:propstat>
         </D:response>
        </D:multistatus>



Dusseault                 Expires May 19, 2006                 [Page 59]

Internet-Draft                 RFC2518bis                  November 2005


   This example shows a request for an exclusive write lock on a
   collection and all its children.  In this request, the client has
   specified that it desires an infinite length lock, if available,
   otherwise a timeout of 4.1 billion seconds, if available.  The
   request entity body contains the contact information for the
   principal taking out the lock, in this case a web page URL.

   The error is a 403 (Forbidden) response on the resource
   http://example.com/webdav/secret.  Because this resource could not be
   locked, none of the resources were locked.  Note also that the
   lockdiscovery property for the Request-URI has been included as
   required.  In this example the lockdiscovery property is empty which
   means that there are no outstanding locks on the resource.

   In this example, the nonce, response, and opaque fields have not been
   calculated in the Authorization request header.

8.12.  UNLOCK Method

   The UNLOCK method removes the lock identified by the lock token in
   the Lock-Token request header.  The Request-URI MUST identify a
   resource within the scope of the lock.  The If header is not needed
   to provide the lock token although servers SHOULD still evaluate the
   If header and treat it as a conditional header.

   For a successful response to this method, the server MUST remove the
   lock from the resource identified by the Request-URI and from all
   other resources included in the lock.

   If all resources which have been locked under the submitted lock
   token can not be unlocked then the UNLOCK request MUST fail.

   A successful response to an UNLOCK method does not mean that the
   resource is necessarily unlocked.  It means that the specific lock
   corresponding to the specified token no longer exists.

   Any DAV compliant resource which supports the LOCK method MUST
   support the UNLOCK method.

8.12.1.  Status Codes

   204 (No Content) - Normal success response (rather than 200 OK, since
   200 OK would imply a response body, and an UNLOCK success response
   does not normally contain a body)

   400 (Bad Request) - No lock token was provided (see 'missing-lock-
   token' precondition), or request was made to a Request-URI that was
   not within the scope of the lock (see 'requesturi-must-match-lock-



Dusseault                 Expires May 19, 2006                 [Page 60]

Internet-Draft                 RFC2518bis                  November 2005


   token' precondition).

   403 (Forbidden) - The currently authenticated principal does not have
   permission to remove the lock (the server SHOULD use the 'need-
   privileges' precondition element).

   412 (Precondition Failed) - The resource was not locked.

8.12.2.  Example

    >>Request

      UNLOCK /workspace/webdav/info.doc HTTP/1.1
      Host: example.com
      Lock-Token: <urn:uuid:a515cfa4-5da4-22e1-f5b5-00a0451e6bf7>
      Authorization: Digest username="ejw",
         realm="ejw@example.com", nonce="...",
         uri="/workspace/webdav/proposal.doc",
         response="...", opaque="..."

    >>Response

      HTTP/1.1 204 No Content

   In this example, the lock identified by the lock token
   "urn:uuid:a515cfa4-5da4-22e1-f5b5-00a0451e6bf7" is successfully
   removed from the resource
   http://example.com/workspace/webdav/info.doc.  If this lock included
   more than just one resource, the lock is removed from all resources
   included in the lock.  The 204 (No Content) status code is used
   instead of 200 (OK) because there is no response entity body.

   In this example, the nonce, response, and opaque fields have not been
   calculated in the Authorization request header.

















Dusseault                 Expires May 19, 2006                 [Page 61]

Internet-Draft                 RFC2518bis                  November 2005


9.  HTTP Headers for Distributed Authoring

   All DAV headers follow the same basic formatting rules as HTTP
   headers.  This includes rules like line continuation and how to
   combine (or separate) multiple instances of the same header using
   commas.

9.1.  DAV Header


      DAV             = "DAV" ":" #( compliance-code )
      compliance-code = ( "1" | "2" | "bis" | extend )
      extend          = Coded-URL | token

   This general-header appearing in the response indicates that the
   resource supports the DAV schema and protocol as specified.  All DAV
   compliant resources MUST return the DAV header on all OPTIONS
   responses.

   The value is a comma-separated list of all compliance class
   identifiers that the resource supports.  Class identifiers may be
   Coded-URLs or tokens (as defined by [RFC2616]).  Identifiers can
   appear in any order.  Identifiers that are standardized through the
   IETF RFC process are tokens, but other identifiers SHOULD be Coded-
   URLs to encourage uniqueness.

   A resource must show class 1 compliance if it shows class 2 or "bis"
   compliance.  In general, support for one compliance class does not
   entail support for any other.  Please refer to section 16 for more
   details on compliance classes defined in this specification.

   This header must also appear on responses to OPTIONS requests to the
   special '*' Request-URI as defined in HTTP/1.1.  In this case it
   means that the repository supports the named features in at least
   some internal namespaces.

   As an optional request header, this header allows the client to
   advertise compliance with named features.  Clients need not advertise
   1, 2 or bis because a WebDAV server currently doesn't need that
   information to decide how to respond to requests defined in this
   specification or in HTTP/1.1.  However, future extensions may define
   client compliance codes.  When used as a request header, the DAV
   header MAY affect caching so this header SHOULD NOT be used on all
   GET requests.

9.2.  Depth Header

      Depth = "Depth" ":" ("0" | "1" | "infinity")



Dusseault                 Expires May 19, 2006                 [Page 62]

Internet-Draft                 RFC2518bis                  November 2005


   The Depth request header is used with methods executed on resources
   which could potentially have internal members to indicate whether the
   method is to be applied only to the resource ("Depth: 0"), to the
   resource and its immediate children, ("Depth: 1"), or the resource
   and all its progeny ("Depth: infinity").

   The Depth header is only supported if a method's definition
   explicitly provides for such support.

   The following rules are the default behavior for any method that
   supports the Depth header.  A method may override these defaults by
   defining different behavior in its definition.

   Methods which support the Depth header may choose not to support all
   of the header's values and may define, on a case by case basis, the
   behavior of the method if a Depth header is not present.  For
   example, the MOVE method only supports "Depth: infinity" and if a
   Depth header is not present will act as if a "Depth: infinity" header
   had been applied.

   Clients MUST NOT rely upon methods executing on members of their
   hierarchies in any particular order or on the execution being atomic
   unless the particular method explicitly provides such guarantees.

   Upon execution, a method with a Depth header will perform as much of
   its assigned task as possible and then return a response specifying
   what it was able to accomplish and what it failed to do.

   So, for example, an attempt to COPY a hierarchy may result in some of
   the members being copied and some not.

   Any headers on a method that has a defined interaction with the Depth
   header MUST be applied to all resources in the scope of the method
   except where alternative behavior is explicitly defined.  For
   example, an If-Match header will have its value applied against every
   resource in the method's scope and will cause the method to fail if
   the header fails to match.

   If a resource, source or destination, within the scope of the method
   with a Depth header is locked in such a way as to prevent the
   successful execution of the method, then the lock token for that
   resource MUST be submitted with the request in the If request header.

   The Depth header only specifies the behavior of the method with
   regards to internal children.  If a resource does not have internal
   children then the Depth header MUST be ignored.

   Please note, however, that it is always an error to submit a value



Dusseault                 Expires May 19, 2006                 [Page 63]

Internet-Draft                 RFC2518bis                  November 2005


   for the Depth header that is not allowed by the method's definition.
   Thus submitting a "Depth: 1" on a COPY, even if the resource does not
   have internal members, will result in a 400 (Bad Request).  The
   method should fail not because the resource doesn't have internal
   members, but because of the illegal value in the header.

9.3.  Destination Header

   Destination = "Destination" ":" ( absolute-URI )

   The Destination request header specifies the URI which identifies a
   destination resource for methods such as COPY and MOVE, which take
   two URIs as parameters.  Note that the absolute-URI production is
   defined in RFC3986 [8].

   If the Destination value is an absolute URI, it may name a different
   server (or different port or scheme).  If the source server cannot
   attempt a copy to the remote server, it MUST fail the request with a
   502 (Bad Gateway) response.  Servers MAY attempt to copy the resource
   to the remote server using PUT/PROPPATCH or another mechanism.

9.4.  Force-Authentication Header

   Force-Authentication = "Force-Authentication" ":" Method

   The Force-Authentication request header is used with the OPTIONS
   method to specify that the client wants to be challenged for
   authentication credentials to the resource identified by the Request-
   URI.  If present on a request to a WebDAV-compliant resource, the
   server MUST respond with either 401 (Unauthorized) or 501 (Not
   Implemented) status code.  The Method value is used for the client to
   indicate what method it intends to use first on the resource
   identified in the Request-URI.

9.5.  If Header

      If = "If" ":" ( 1*No-tag-list | 1*Tagged-list)
      No-tag-list = List
      Tagged-list = Resource 1*List
      Resource = Coded-URL
      List = #( "(" List | Clause ")" )
      Clause = ["Not"] State-token | State-token
      State-token = Coded-URL  | "[" entity-tag "]"
      Coded-URL = "<" absolute-URI ">"

   The If request header is intended to have similar functionality to
   the If-Match header defined in section 14.24 of RFC2616 [6].  However
   the If header is intended for use with any URI which represents state



Dusseault                 Expires May 19, 2006                 [Page 64]

Internet-Draft                 RFC2518bis                  November 2005


   information, referred to as a state token, about a resource as well
   as ETags.  A typical example of a state token is a lock token, and
   lock tokens are the only state tokens defined in this specification.
   The <DAV:no-lock> state token is an example of a state token that
   will never match an actual valid lock token.  The purpose of this is
   described in Section 9.5.3.

   The If header's purpose is to describe a series of state lists.  If
   the state of the resource to which the header is applied does not
   match any of the specified state lists then the request MUST fail
   with a 412 (Precondition Failed).  If one of the described state
   lists matches the state of the resource then the request may succeed.

   The server must parse the If header when it appears on any request,
   evaluate all the clauses, and if the conditional evaluates to false,
   fail the request.

   Note that the absolute-URI production is defined in RFC3986 [8].

   RFC2518 originally defined the If header without comma separators.
   This oversight meant that the If header couldn't be divided up among
   multiple lines according to the HTTP header manipulation rules.
   Servers supporting "bis" MUST be able to accept commas in If header
   values.  If the header has commas between tokens or clauses, the
   header can be evaluated simply by removing the commas and proceeding
   with the evaluation rules.

9.5.1.  No-tag-list Production

   The No-tag-list production describes a series of state tokens and
   ETags.  If multiple No-tag-list productions are used then one only
   needs to match the state of the resource for the method to be allowed
   to continue.  All untagged tokens apply to the resource identified in
   the Request-URI.

   Example - no-tag-list production

      If: (<urn:uuid:181d4fae-7d8c-11d0-a765-00a0c91e6bf2>
             ["I am an ETag"]), (["I am another ETag"])

   The previous header would require that the resource identified in the
   Request-URI be locked with the specified lock token and in the state
   identified by the "I am an ETag" ETag or in the state identified by
   the second ETag "I am another ETag".  To put the matter more plainly
   one can think of the previous If header as being in the form (or (and
   <urn:uuid:181d4fae-7d8c-11d0-a765-00a0c91e6bf2> ["I am an ETag"])
   (and ["I am another ETag"])).




Dusseault                 Expires May 19, 2006                 [Page 65]

Internet-Draft                 RFC2518bis                  November 2005


9.5.2.  Tagged-list Production

   The tagged-list production may be used instead of the no-tag-list
   production, in order to scope each token to a specific resource.
   That is, it specifies that the lists following the resource
   specification only apply to the specified resource.  The scope of the
   resource production begins with the list production immediately
   following the resource production and ends with the next resource
   production, if any.  All clauses must be evaluated.  If the state of
   the resource named in the tag does not match any of the associated
   state lists then the request MUST fail with a 412 (Precondition
   Failed).  The tagged-list production MUST NOT be used together with
   the no-tag-list production, either in the same If header or in a
   continuation.

   The same URI MUST NOT appear more than once in a resource production
   in an If header.

   Example - Tagged List If header

        COPY /resource1 HTTP/1.1
        Host: www.example.com
        Destination: http://www.example.com/resource2
        If: <http://www.example.com/resource1>
              (<urn:uuid:181d4fae-7d8c-11d0-a765-00a0c91e6bf2>
              [W/"A weak ETag"]), (["strong ETag"]),
            <http://www.bar.bar/random>
             (["another strong ETag"])

   In this example http://www.example.com/resource1 is being copied to
   http://www.example.com/resource2.  When the method is first applied
   to http://www.example.com/resource1, resource1 must be in the state
   specified by "(<urn:uuid:181d4fae-7d8c-11d0-a765-00a0c91e6bf2> [W/"A
   weak ETag"]) (["strong ETag"])", that is, it either must be locked
   with a lock token of "urn:uuid:181d4fae-7d8c-11d0-a765-00a0c91e6bf2"
   and have a weak entity tag W/"A weak ETag" or it must have a strong
   entity tag "strong ETag".

   That is the only success condition since the resource
   http://www.bar.bar/random never has the method applied to it (the
   only other resource listed in the If header) and
   http://www.example.com/resource2 is not listed in the If header.

9.5.3.  Not Production

   Every state token or ETag is either current, and hence describes the
   state of a resource, or is not current, and does not describe the
   state of a resource.  The boolean operation of matching a state token



Dusseault                 Expires May 19, 2006                 [Page 66]

Internet-Draft                 RFC2518bis                  November 2005


   or ETag to the current state of a resource thus resolves to a true or
   false value.  The "Not" production is used to reverse that value.
   The scope of the not production is the state-token or entity-tag
   immediately following it.

        If: (Not <urn:uuid:181d4fae-7d8c-11d0-a765-00a0c91e6bf2>
             <urn:uuid:58f202ac-22cf-11d1-b12d-002035b29092>)

   When submitted with a request, this If header requires that all
   operand resources must not be locked with
   urn:uuid:181d4fae-7d8c-11d0-a765-00a0c91e6bf2 and must be locked with
   urn:uuid:58f202ac-22cf-11d1-b12d-002035b29092.

   The Not production is particularly useful with the "<DAV:no-lock>"
   state token.  The clause "Not <DAV:no-lock>" MUST evaluate to true.
   Thus, any "OR" statement containing the clause "Not <DAV:no-lock>"
   MUST also evaluate to true.

9.5.4.  Matching Function

   When performing If header processing, the definition of a matching
   state token or entity tag is as follows.

   Identifying a resource: The resource is identified by the URI along
   with the token, in tagged list production, or by the Request-URI in
   untagged list production.

   Matching entity tag: Where the entity tag matches an entity tag
   associated with the identified resource.

   Matching state token: Where there is an exact match between the state
   token in the If header and any state token on the identified
   resource.  A lock state token is considered to match if the resource
   is anywhere in the scope of the lock.

   Example - Matching lock tokens with collection locks

    DELETE /specs/rfc2518.txt HTTP/1.1
    Host: www.example.com
    If: <http://www.example.com/specs/>
          (<urn:uuid:181d4fae-7d8c-11d0-a765-00a0c91e6bf2>)

   For this example, the lock token must be compared to the identified
   resource, which is the 'specs' collection identified by the URL in
   the tagged list production.  If the 'specs' collection is not locked
   or has a lock with a different token, the request MUST fail.  If the
   'specs' collection is locked (depth infinity) with that lock token,
   then this request could succeed, both because the If header evaluates



Dusseault                 Expires May 19, 2006                 [Page 67]

Internet-Draft                 RFC2518bis                  November 2005


   to true, and because the lock token for the lock affecting the
   affected resource has been provided.  Alternatively, a request where
   the 'rfc2518.txt' URL is associated with the lock token in the If
   header could also succeed.

9.5.5.  If Header and Non-DAV Aware Proxies

   Non-DAV aware proxies will not honor the If header, since they will
   not understand the If header, and HTTP requires non-understood
   headers to be ignored.  When communicating with HTTP/1.1 proxies, the
   "Cache-Control: no-cache" request header MUST be used so as to
   prevent the proxy from improperly trying to service the request from
   its cache.  When dealing with HTTP/1.0 proxies the "Pragma: no-
   cache" request header MUST be used for the same reason.

9.6.  Lock-Token Header

   Lock-Token = "Lock-Token" ":" Coded-URL

   The Lock-Token request header is used with the UNLOCK method to
   identify the lock to be removed.  The lock token in the Lock-Token
   request header MUST identify a lock that contains the resource
   identified by Request-URI as a member.

   The Lock-Token response header is used with the LOCK method to
   indicate the lock token created as a result of a successful LOCK
   request to create a new lock.

9.7.  Overwrite Header

   Overwrite = "Overwrite" ":" ("T" | "F")

   The Overwrite request header specifies whether the server should
   overwrite the state of a non-null destination resource during a COPY
   or MOVE.  A value of "F" states that the server must not perform the
   COPY or MOVE operation if the state of the destination resource is
   non-null.  If the overwrite header is not included in a COPY or MOVE
   request then the resource MUST treat the request as if it has an
   overwrite header of value "T".  While the Overwrite header appears to
   duplicate the functionality of the If-Match: * header of HTTP/1.1,
   If-Match applies only to the Request-URI, and not to the Destination
   of a COPY or MOVE.

   If a COPY or MOVE is not performed due to the value of the Overwrite
   header, the method MUST fail with a 412 (Precondition Failed) status
   code.

   All DAV compliant resources MUST support the Overwrite header.



Dusseault                 Expires May 19, 2006                 [Page 68]

Internet-Draft                 RFC2518bis                  November 2005


9.8.  Timeout Request Header

      TimeOut = "Timeout" ":" 1#TimeType
      TimeType = ("Second-" DAVTimeOutVal | "Infinite")
      DAVTimeOutVal = 1*digit

   Clients may include Timeout request headers in their LOCK requests.
   However, the server is not required to honor or even consider these
   requests.  Clients MUST NOT submit a Timeout request header with any
   method other than a LOCK method.

   Timeout response values MUST use a Second value or Infinite.

   The "Second" TimeType specifies the number of seconds that will
   elapse between granting of the lock at the server, and the automatic
   removal of the lock.  The timeout value for TimeType "Second" MUST
   NOT be greater than 2^32-1.

   The timeout counter MUST be restarted if a refresh LOCK request is
   successful.  The timeout counter SHOULD NOT be restarted at any other
   time.

   If the timeout expires then the lock may be lost.  Specifically, if
   the server wishes to harvest the lock upon time-out, the server
   SHOULD act as if an UNLOCK method was executed by the server on the
   resource using the lock token of the timed-out lock, performed with
   its override authority.  Thus logs should be updated with the
   disposition of the lock, notifications should be sent, etc., just as
   they would be for an UNLOCK request.

   Servers are advised to pay close attention to the values submitted by
   clients, as they will be indicative of the type of activity the
   client intends to perform.  For example, an applet running in a
   browser may need to lock a resource, but because of the instability
   of the environment within which the applet is running, the applet may
   be turned off without warning.  As a result, the applet is likely to
   ask for a relatively small timeout value so that if the applet dies,
   the lock can be quickly harvested.  However, a document management
   system is likely to ask for an extremely long timeout because its
   user may be planning on going off-line.

   A client MUST NOT assume that just because the time-out has expired
   the lock has been lost.  Likewise, a client MUST NOT assume that just
   because the time-out has not expired, the lock still exists (and for
   this reason, clients are strongly advised to use ETags as well).






Dusseault                 Expires May 19, 2006                 [Page 69]

Internet-Draft                 RFC2518bis                  November 2005


10.  Status Code Extensions to HTTP/1.1

   The following status codes are added to those defined in HTTP/1.1
   RFC2616 [6].

10.1.  102 Processing

   The 102 (Processing) status code is an interim response used to
   inform the client that the server has accepted the complete request,
   but has not yet completed it.  This status code SHOULD only be sent
   when the server has a reasonable expectation that the request will
   take significant time to complete.  As guidance, if a method is
   taking longer than 20 seconds (a reasonable, but arbitrary value) to
   process the server SHOULD return a 102 (Processing) response.  The
   server MUST send a final response after the request has been
   completed.

   Methods can potentially take a long period of time to process,
   especially methods that support the Depth header.  In such cases the
   client may time-out the connection while waiting for a response.  To
   prevent this the server may return a 102 (Processing) status code to
   indicate to the client that the server is still processing the
   method.

10.2.  207 Multi-Status

   The 207 (Multi-Status) status code provides status for multiple
   independent operations (see Section 12 for more information).

10.3.  422 Unprocessable Entity

   The 422 (Unprocessable Entity) status code means the server
   understands the content type of the request entity (hence a
   415(Unsupported Media Type) status code is inappropriate), and the
   syntax of the request entity is correct (thus a 400 (Bad Request)
   status code is inappropriate) but was unable to process the contained
   instructions.  For example, this error condition may occur if an XML
   request body contains well-formed (i.e., syntactically correct), but
   semantically erroneous XML instructions.

10.4.  423 Locked

   The 423 (Locked) status code means the source or destination resource
   of a method is locked.  This response SHOULD contain the 'missing-
   lock-token' element and corresponding href in the error body.






Dusseault                 Expires May 19, 2006                 [Page 70]

Internet-Draft                 RFC2518bis                  November 2005


10.5.  424 Failed Dependency

   The 424 (Failed Dependency) status code means that the method could
   not be performed on the resource because the requested action
   depended on another action and that action failed.  For example, if a
   command in a PROPPATCH method fails then, at minimum, the rest of the
   commands will also fail with 424 (Failed Dependency).

10.6.  507 Insufficient Storage

   The 507 (Insufficient Storage) status code means the method could not
   be performed on the resource because the server is unable to store
   the representation needed to successfully complete the request.  This
   condition is considered to be temporary.  If the request which
   received this status code was the result of a user action, the
   request MUST NOT be repeated until it is requested by a separate user
   action.


































Dusseault                 Expires May 19, 2006                 [Page 71]

Internet-Draft                 RFC2518bis                  November 2005


11.  Use of HTTP Status Codes

   These HTTP codes are not redefined, but this section serves as a
   reminder that these HTTP codes may be used in responses to WebDAV
   methods and clients must be appropriately prepared to handle them.

11.1.  301 Moved Permanently

   A server MAY use this status code in response to any request.

11.2.  302 Found

   A server MAY use this status code in response to any request.

11.3.  400 Bad Request

   A server MAY use this status code in response to any request.  Some
   possible reasons:

   o  the Host header is missing in any request

   o  The protocol version is HTTP/1.0

   o  Any header is improperly formatted

   o  The request method line is improperly formatted

11.4.  403 Forbidden

   A server MAY use this status code in response to any request.  An
   appropriate use example would be in response to a PUT request to a
   collection, if the server does not ever allow PUT to a collection.

11.5.  409 Conflict

   A server MAY use this status code in response to any request.  In
   base WebDAV, the 409 Conflict is most typically returned when a
   method that attempts to create a new resource must fail, because one
   of the collections that resource depends on does not exist.  However,
   other types of conflicts are defined in specifications extending
   RFC2518.

11.6.  412 Precondition Failed

   Any request can contain a conditional header defined in HTTP (If-
   Match, If-Modified-Since, etc.) or the "If" conditional header
   defined in this specification.  If the request contains a conditional
   header, and if that condition fails to hold, then this error code



Dusseault                 Expires May 19, 2006                 [Page 72]

Internet-Draft                 RFC2518bis                  November 2005


   MUST be returned unless some other error is returned.  On the other
   hand, if the client did not include a conditional header in the
   request, then the server MUST NOT use this error.

11.7.  414 Request-URI Too Long

   This status code is used in HTTP 1.1 only for Request-URIs, because
   full URIs aren't used in other headers.  WebDAV specifies full URLs
   in other headers, therefore this error may be used if the URI is too
   long in other locations as well.  A server MAY use this status code
   in response to any request.

11.8.  503 Service Unavailable

   This status code is particularly useful to respond to requests that
   the server considers a denial-of-service attack, such as excessively
   large PROPFIND depth infinity requests or requests in quick
   succession.  A server MAY use this status code in response to any
   request, provided that the request did not partially or completely
   succeed.































Dusseault                 Expires May 19, 2006                 [Page 73]

Internet-Draft                 RFC2518bis                  November 2005


12.  Multi-Status Response

   A Multi-Status response contains one 'response' element for each
   resource in the scope of the request (in no required order) or may be
   empty if no resources match the request.  The default 207 (Multi-
   Status) response body is a text/xml or application/xml HTTP entity
   that contains a single XML element called multistatus, which contains
   a set of XML elements called response which contain 200, 300, 400,
   and 500 series status codes generated during the method invocation.
   100 series status codes SHOULD NOT be recorded in a response XML
   element.  The 207 status code itself MUST NOT be considered a success
   response, it is only completely successful if all response elements
   inside contain success status codes.

   The body of a 207 Multi-Status response MUST contain a URL associated
   with each specific status code, so that the client can tell whether
   the error occurred with the source resource, destination resource or
   some other resource in the scope of the request.

12.1.  Response headers

   Use of the Location header with the Multi-Status response is
   intentionally undefined.  Note that this specification does not
   define a way to redirect requests for individual resources within the
   scope of a Multi-Status response.  The server MAY always redirect the
   entire request by responding with a 300 level status response instead
   of a Multi-Status response.

12.2.  URL handling

   When a Multi-Status body is returned in response to a PROPFIND or
   another request with a single scope, all URLs appearing in the body
   must be equal to or inside the request-URI, thus the URLs MAY be
   absolute or MAY be relative.

   o  If the URLs are absolute, then the server MUST ensure that the
      URLs have the same prefix (scheme, host, port, and path) as the
      URL of the requested resource.

   o  If the URLs are relative, they MUST be resolved against the
      Request-URI.

   When a Multi-Status body is returned in response to MOVE or COPY,
   relative URI resolution is ambiguous (the request had both a source
   and a destination URL).  Thus, URLs appearing in the responses to
   MOVE or COPY SHOULD be absolute and fully-qualified URLs.

   Servers MUST NOT return "." or ".." within an absolute or relative



Dusseault                 Expires May 19, 2006                 [Page 74]

Internet-Draft                 RFC2518bis                  November 2005


   URI returned within a Multi-Status response.

   URLs for collections appearing in the results SHOULD end in a '/'
   character.

   If a server allows resource names to include characters that aren't
   legal in HTTP URL paths, these characters must be URI-escaped on the
   wire.  For example, it is illegal to use a space character or double-
   quote in a URI [8].  URIs appearing in PROPFIND or PROPPATCH XML
   bodies (or other XML marshalling defined in this specification) are
   still subject to all URI rules, including forbidden characters.

12.3.  Internal Status Codes

   Section 8.3.1, Section 8.2.2, Section 8.7.2, Section 8.9.3 and
   Section 8.10.2 define various status codes used in Multi-Status
   responses.  This specification does not define the meaning of other
   status codes that could appear in these responses.

































Dusseault                 Expires May 19, 2006                 [Page 75]

Internet-Draft                 RFC2518bis                  November 2005


13.  XML Element Definitions

   In this section, the final line of each section gives the element
   type declaration using the format defined in XML [11].  The "Value"
   field, where present, specifies further restrictions on the allowable
   contents of the XML element using BNF (i.e., to further restrict the
   values of a PCDATA element).  The "Extensibility" field discusses how
   the element may be extended in the future (or in existing extensions
   to WebDAV.

   All of the elements defined here may be extended by the addition of
   attributes and child elements not defined in this specification.

13.1.  activelock XML Element

   Name:  activelock

   Namespace:  DAV:

   Purpose:  Describes a lock on a resource.

   Extensibility:  MAY be extended with additional child elements or
      attributes which SHOULD be ignored if not recognized.


   <!ELEMENT activelock (lockscope, locktype, depth, owner?, timeout?,
   locktoken?, lockroot)>

13.2.  depth XML Element

   Name:  depth

   Namespace:  DAV:

   Purpose:  The value of the Depth header.

   Value:  "0" | "1" | "infinity"

   Extensibility:  MAY be extended with attributes which SHOULD be
      ignored.

   <!ELEMENT depth (#PCDATA) >

13.3.  locktoken XML Element







Dusseault                 Expires May 19, 2006                 [Page 76]

Internet-Draft                 RFC2518bis                  November 2005


   Name:  locktoken

   Namespace:  DAV:

   Purpose:  The lock token associated with a lock.

   Description:  The href contains a single lock token URI which refers
      to the lock.

   Extensibility:  MAY be extended with additional child elements or
      attributes which SHOULD be ignored if not recognized.

   <!ELEMENT locktoken (href) >

13.4.  lockroot XML Element

   Name:  lockroot

   Namespace:  DAV:

   Purpose:  Contains the root URL of the lock, which is the URL through
      which the resource was addressed in the LOCK request.

   Description:  The href contains a URL with the address of the root of
      the lock.  The server SHOULD include this in all lockdiscovery
      property values and the response to LOCK requests.

   Extensibility:  MAY be extended with additional child elements or
      attributes which SHOULD be ignored if not recognized.

   <!ELEMENT lockroot (href) >

13.5.  timeout XML Element

   Name:  timeout

   Namespace:  DAV:

   Purpose:  The number of seconds remaining before a lock expires.

   Value:  TimeType (defined in Section 9.8).

   Extensibility:  MAY be extended with attributes which SHOULD be
      ignored.


      <!ELEMENT timeout (#PCDATA) >




Dusseault                 Expires May 19, 2006                 [Page 77]

Internet-Draft                 RFC2518bis                  November 2005


13.6.  collection XML Element

   Name:  collection

   Namespace:  DAV:

   Purpose:  Identifies the associated resource as a collection.  The
      resourcetype property of a collection resource MUST contain this
      element.  It is normally empty but extensions may add sub-
      elements.

   Extensibility:  MAY be extended with child elements or attributes
      which SHOULD be ignored if not recognized.

   <!ELEMENT collection EMPTY >

13.7.  href XML Element

   Name:  href

   Namespace:  DAV:

   Purpose:  Identifies the content of the element as a URI.  In many
      situations, this URI MUST be a HTTP URI, and furthermore, it MUST
      identify a WebDAV resource.  There is one exception to this
      general rule in the lockdiscovery property, where the lock token
      (which is a URI but may not be a HTTP URI) is inside the href
      element.  Other specifications SHOULD be explicit if the href
      element is to contain non-HTTP URIs.

   Value:  URI (See section 3.2.1 of RFC2616 [6])

   Extensibility:  MAY be extended with attributes which SHOULD be
      ignored.


      <!ELEMENT href (#PCDATA)>

13.8.  lockentry XML Element

   Name:  lockentry

   Namespace:  DAV:

   Purpose:  Defines the types of locks that can be used with the
      resource.





Dusseault                 Expires May 19, 2006                 [Page 78]

Internet-Draft                 RFC2518bis                  November 2005


   Extensibility:  MAY be extended with additional child elements or
      attributes which SHOULD be ignored if not recognized.

   <!ELEMENT lockentry (lockscope, locktype) >

13.9.  lockinfo XML Element

   Name:  lockinfo

   Namespace:  DAV:

   Purpose:  The lockinfo XML element is used with a LOCK method to
      specify the type of lock the client wishes to have created.

   Extensibility:  MAY be extended with additional child elements or
      attributes which SHOULD be ignored if not recognized.


   <!ELEMENT lockinfo (lockscope, locktype, owner?)  >

13.10.  lockscope XML Element

   Name:  lockscope

   Namespace:  DAV:

   Purpose:  Specifies whether a lock is an exclusive lock, or a shared
      lock.

   Extensibility:  SHOULD NOT be extended with child elements.  MAY be
      extended with attributes which SHOULD be ignored.


     <!ELEMENT lockscope (exclusive | shared) >


13.11.  exclusive XML Element

   Name:  exclusive

   Namespace:  DAV:

   Purpose:  Specifies an exclusive lock

   Extensibility:  Normally empty, but MAY be extended with additional
      child elements or attributes which SHOULD be ignored if not
      recognized.




Dusseault                 Expires May 19, 2006                 [Page 79]

Internet-Draft                 RFC2518bis                  November 2005


   <!ELEMENT exclusive EMPTY >


13.12.  shared XML Element

   Name:  shared

   Namespace:  DAV:

   Purpose:  Specifies a shared lock

   Extensibility:  Normally empty, but MAY be extended with additional
      child elements or attributes which SHOULD be ignored if not
      recognized.


   <!ELEMENT shared EMPTY >


13.13.  locktype XML Element

   Name:  locktype

   Namespace:  DAV:

   Purpose:  Specifies the access type of a lock.  At present, this
      specification only defines one lock type, the write lock.

   Extensibility:  MAY be extended with additional child elements or
      attributes which SHOULD be ignored if not recognized.


   <!ELEMENT locktype (write) >


13.14.  write XML Element

   Name:  write

   Namespace:  DAV:

   Purpose:  Specifies a write lock.

   Extensibility:  Normally empty, but MAY be extended with additional
      child elements or attributes which SHOULD be ignored if not
      recognized.





Dusseault                 Expires May 19, 2006                 [Page 80]

Internet-Draft                 RFC2518bis                  November 2005


   <!ELEMENT write EMPTY >


13.15.  multistatus XML Element

   Name:  multistatus

   Namespace:  DAV:

   Purpose:  Contains multiple response messages.

   Description The responsedescription at the top level is used to
      provide a general message describing the overarching nature of the
      response.  If this value is available an application may use it
      instead of presenting the individual response descriptions
      contained within the responses.

   Extensibility:  MAY be extended with additional child elements or
      attributes which SHOULD be ignored if not recognized.


   <!ELEMENT multistatus (response+, responsedescription?)  >


13.16.  response XML Element

   Name:  locktype

   Namespace:  DAV:

   Purpose:  Holds a single response describing the effect of a method
      on resource and/or its properties.

   Description:  A particular href MUST NOT appear more than once as the
      child of a response XML element under a multistatus XML element.
      This requirement is necessary in order to keep processing costs
      for a response to linear time.  Essentially, this prevents having
      to search in order to group together all the responses by href.
      There are, however, no requirements regarding ordering based on
      href values.

   Extensibility:  MAY be extended with additional child elements or
      attributes which SHOULD be ignored if not recognized.


   <!ELEMENT response (href, ((href*, status)|(propstat+)),
         responsedescription? , location?) >




Dusseault                 Expires May 19, 2006                 [Page 81]

Internet-Draft                 RFC2518bis                  November 2005


13.17.  propstat XML Element

   Name:  propstat

   Namespace:  DAV:

   Purpose:  Groups together a prop and status element that is
      associated with a particular href element.

   Description:  The propstat XML element MUST contain one prop XML
      element and one status XML element.  The contents of the prop XML
      element MUST only list the names of properties to which the result
      in the status element applies.

   Extensibility:  MAY be extended with additional child elements or
      attributes which SHOULD be ignored if not recognized.

   <!ELEMENT propstat (prop, status, responsedescription?) >

13.18.  status XML Element

   Name:  status

   Namespace:  DAV:

   Purpose:  Holds a single HTTP status-line

   Value:  status-line (status-line defined in RFC2616 [6]

   Extensibility:  MAY be extended with attributes which SHOULD be
      ignored.

   <!ELEMENT status (#PCDATA) >

13.19.  responsedescription XML Element

   Name:  responsedescription

   Namespace:  DAV:

   Purpose:  Contains a message that can be displayed to the user
      explaining the nature of the response.

   Description:  This XML element provides information suitable to be
      presented to a user.






Dusseault                 Expires May 19, 2006                 [Page 82]

Internet-Draft                 RFC2518bis                  November 2005


   Extensibility:  MAY be extended with attributes which SHOULD be
      ignored.

   <!ELEMENT responsedescription (#PCDATA) >

13.20.  owner XML Element

   Name:  owner

   Namespace:  DAV:

   Purpose:  Provides information about the principal taking out a lock.

   Description The owner XML element provides information sufficient for
      either directly contacting a principal (such as a telephone number
      or Email URI), or for discovering the principal (such as the URL
      of a homepage) who owns a lock.  This information is provided by
      the client, and may only be altered by the server if the owner
      value provided by the client is empty.

   Extensibility MAY be extended with child elements, mixed content,
      text content or attributes.  Structured content, for example one
      or more <href> child elements containing URLs, is RECOMMENDED.

   <!ELEMENT owner ANY >

13.21.  prop XML element

   Name:  prop

   Namespace:  DAV:

   Purpose:  Contains properties related to a resource.

   Description The prop XML element is a generic container for
      properties defined on resources.  All elements inside a prop XML
      element MUST define properties related to the resource.  No other
      elements may be used inside of a prop element.

   Extensibility MAY be extended with attributes which SHOULD be ignored
      if not recognized.  Any child element of this element must be
      considered to be a property name, however these are not restricted
      to the property names defined in this document or other standards.

   <!ELEMENT prop ANY >






Dusseault                 Expires May 19, 2006                 [Page 83]

Internet-Draft                 RFC2518bis                  November 2005


13.22.  propertyupdate XML element

   Name:  propertyupdate

   Namespace:  DAV:

   Purpose:  Contains a request to alter the properties on a resource.

   Description:  This XML element is a container for the information
      required to modify the properties on the resource.  This XML
      element is multi-valued.

   Extensibility:  MAY be extended with additional child elements or
      attributes which SHOULD be ignored if not recognized.

   <!ELEMENT propertyupdate (remove | set)+ >

13.23.  remove XML element

   Name:  remove

   Namespace:  DAV:

   Purpose:  Lists the DAV properties to be removed from a resource.

   Description:  Remove instructs that the properties specified in prop
      should be removed.  Specifying the removal of a property that does
      not exist is not an error.  All the XML elements in a prop XML
      element inside of a remove XML element MUST be empty, as only the
      names of properties to be removed are required.

   Extensibility:  MAY be extended with additional child elements or
      attributes which SHOULD be ignored if not recognized.

   <!ELEMENT remove (prop) >

13.24.  set XML element

   Name:  set

   Namespace:  DAV:

   Purpose:  Lists the DAV property values to be set for a resource.

   Description:  The set XML element MUST contain only a prop XML
      element.  The elements contained by the prop XML element inside
      the set XML element MUST specify the name and value of properties
      that are set on the resource identified by Request-URI.  If a



Dusseault                 Expires May 19, 2006                 [Page 84]

Internet-Draft                 RFC2518bis                  November 2005


      property already exists then its value is replaced.  Language
      tagging information appearing in the scope of the prop element (in
      the "xml:lang" attribute, if present) MUST be persistently stored
      along with the property, and MUST be subsequently retrievable
      using PROPFIND.

   Extensibility:  MAY be extended with additional child elements or
      attributes which SHOULD be ignored if not recognized.

   <!ELEMENT set (prop) >

13.25.  propfind XML Element

   Name:  propfind

   Namespace:  DAV:

   Purpose:  Specifies the properties to be returned from a PROPFIND
      method.  Four special elements are specified for use with
      propfind: prop, dead-props, allprop and propname.  If prop is used
      inside propfind it MUST NOT contain property values.

   Extensibility:  MAY be extended with additional child elements or
      attributes which SHOULD be ignored if not recognized, as long as
      it still contains one of the required elements.

   <!ELEMENT propfind (prop | dead-props | propname | allprop) >

13.26.  allprop XML Element

   Name:  allprop

   Namespace:  DAV:

   Purpose:  The allprop XML element specifies that all names and values
      of dead properties and the live properties defined by this
      document existing on the resource are to be returned.

   Extensibility:  Normally empty, but MAY be extended with additional
      child elements or attributes which SHOULD be ignored if not
      recognized.

   <!ELEMENT allprop EMPTY >

13.27.  propname XML Element






Dusseault                 Expires May 19, 2006                 [Page 85]

Internet-Draft                 RFC2518bis                  November 2005


   Name:  propname

   Namespace:  DAV:

   Purpose:  The propname XML element specifies that only a list of
      property names on the resource is to be returned.

   Extensibility:  Normally empty, but MAY be extended with additional
      child elements or attributes which SHOULD be ignored if not
      recognized.

   <!ELEMENT propname EMPTY >

13.28.  dead-props XML Element

   Name:  dead-props

   Namespace:  DAV:

   Purpose:  The dead-props XML element specifies that all dead
      properties, names and values, should be returned in the response.

   Extensibility:  Normally empty, but MAY be extended with additional
      child elements or attributes which SHOULD be ignored if not
      recognized.

   <!ELEMENT dead-props EMPTY >

13.29.  error XML Element

   Name:  error

   Namespace:  DAV:

   Purpose:  Error responses, particularly 403 Forbidden and 409
      Conflict, sometimes need more information to indicate what went
      wrong.  When an error response contains a body in WebDAV, the body
      is in XML with the root element 'error'.  The 'error' tag SHOULD
      include a standard error tag defined in this specification or
      another specification.  The 'error' tag MAY include custom error
      tags (in custom namespaces) which a client can safely ignore.

   Description:  Contains any XML element

   Extensibility:  Fully extensible with additional child elements or
      attributes which SHOULD be ignored if not recognized.

   <!ELEMENT error ANY >



Dusseault                 Expires May 19, 2006                 [Page 86]

Internet-Draft                 RFC2518bis                  November 2005


14.  DAV Properties

   For DAV properties, the name of the property is also the same as the
   name of the XML element that contains its value.  In the section
   below, the final line of each section gives the element type
   declaration using the format defined in XML [11].  The "Value" field,
   where present, specifies further restrictions on the allowable
   contents of the XML element using BNF (i.e., to further restrict the
   values of a PCDATA element).  Note that a resource may have only one
   value for a property of a given name, so the property may only show
   up once in PROPFIND responses or PROPPATCH requests.

   Some property values are calculated by the server and it is not
   appropriate to allow client changes, thus they are protected.
   Existing server implementations already have different sets of
   RFC2518 properties protected, but clients can have some expectations
   which properties are normally protected.  The value of a protected
   property may not be changed even by a user with permission to edit
   other properties.  The value of an unprotected property may be
   changed by some users with appropriate permissions.

14.1.  creationdate Property

   Name:  creationdate

   Namespace:  DAV:

   Purpose:  Records the time and date the resource was created.

   Value:  date-time (defined in RFC3339 [7], see the ABNF in section
      5.6.)

   Protected:  MAY be protected.  Some servers allow creationdate to be
      changed to reflect the time the document was created if that is
      more meaningful to the user (rather than the time it was
      uploaded).  Thus, clients SHOULD NOT use this property in
      synchronization logic (use getetag instead).

   COPY/MOVE behaviour:  This property value SHOULD be kept during a
      MOVE operation, but is normally re-initialized when a resource is
      created with a COPY.  It should not be set in a COPY.

   Description:  The creationdate property should be defined on all DAV
      compliant resources.  If present, it contains a timestamp of the
      moment when the resource was created (i.e., the moment it had non-
      null state).





Dusseault                 Expires May 19, 2006                 [Page 87]

Internet-Draft                 RFC2518bis                  November 2005


   Extensibility:  MAY contain attributes which SHOULD be ignored if not
      recognized.

   <!ELEMENT creationdate (#PCDATA) >

14.2.  displayname Property

   Name:  displayname

   Namespace:  DAV:

   Purpose:  Provides a name for the resource that is suitable for
      presentation to a user.

   Value:  Any text

   Protected:  Possibly

   COPY/MOVE behaviour:  This property value SHOULD be preserved in
      local COPY and MOVE operations.  It MAY be attempted to be set in
      a COPY operation to a remote server.

   Description:  The displayname property should be defined on all DAV
      compliant resources.  If present, the property contains a
      description of the resource that is suitable for presentation to a
      user.

   Extensibility:  MAY contain attributes which SHOULD be ignored if not
      recognized.

   <!ELEMENT displayname (#PCDATA) >

14.3.  getcontentlanguage Property

   Name:  getcontentlanguage

   Namespace:  DAV:

   Purpose:  Contains the Content-Language header returned by a GET
      without accept headers

   Value:  language-tag (language-tag is defined in section 14.13 of
      RFC2616 [6])

   Protected:  SHOULD NOT be protected, so that clients can reset the
      language.





Dusseault                 Expires May 19, 2006                 [Page 88]

Internet-Draft                 RFC2518bis                  November 2005


   COPY/MOVE behaviour:  This property value SHOULD be preserved in
      local COPY and MOVE operations.  It SHOULD be attempted to be set
      in a COPY operation to a remote server.

   Description:  The getcontentlanguage property MUST be defined on any
      DAV compliant resource that returns the Content-Language header on
      a GET.

   Extensibility:  MAY contain attributes which SHOULD be ignored if not
      recognized.

   <!ELEMENT getcontentlanguage (#PCDATA) >

14.4.  getcontentlength Property

   Name:  getcontentlength

   Namespace:  DAV:

   Purpose:  Contains the Content-Length header returned by a GET
      without accept headers.

   Value:  content-length (see section 14.14 of RFC2616 [6])

   Protected:  SHOULD be protected so clients cannot set to misleading
      values

   Description:  The getcontentlength property MUST be defined on any
      DAV compliant resource that returns the Content-Length header in
      response to a GET.

   COPY/MOVE behaviour:  This property value is dependent on the size of
      the destination resource, not the value of the property on the
      source resource.

   Extensibility:  MAY contain attributes which SHOULD be ignored if not
      recognized.

   <!ELEMENT getcontentlength (#PCDATA) >

14.5.  getcontenttype Property

   Name:  getcontenttype

   Namespace:  DAV:






Dusseault                 Expires May 19, 2006                 [Page 89]

Internet-Draft                 RFC2518bis                  November 2005


   Purpose:  Contains the Content-Type header returned by a GET without
      accept headers.

   Value:  media-type (defined in section 3.7 of RFC2616 [6])

   Protected:  SHOULD NOT be protected, so clients may fix this value

   COPY/MOVE behaviour:  This property value SHOULD be preserved in
      local COPY and MOVE operations.  In a remote COPY operation that
      is implemented through a PUT request, the PUT request must have
      the appropriate Content-Type header.

   Description:  This getcontenttype property MUST be defined on any DAV
      compliant resource that returns the Content-Type header in
      response to a GET.

   Extensibility:  MAY contain attributes which SHOULD be ignored if not
      recognized.

   <!ELEMENT getcontenttype (#PCDATA) >

14.6.  getetag Property

   Name:  getetag

   Namespace:  DAV:

   Purpose:  Contains the ETag header returned by a GET without accept
      headers.

   Value:  entity-tag (defined in section 3.11 of RFC2616 [6])

   Protected: MUST be protected because this value is created and
      controlled by the server.

   COPY/MOVE behaviour:  This property value is dependent on the final
      state of the destination resource, not the value of the property
      on the source resource.

   Description:  The getetag property MUST be defined on any DAV
      compliant resource that returns the Etag header.  Refer to RFC2616
      for a complete definition of the semantics of an ETag.  Note that
      changes in properties or lock state MUST not cause a resource's
      ETag to change.







Dusseault                 Expires May 19, 2006                 [Page 90]

Internet-Draft                 RFC2518bis                  November 2005


   Extensibility:  MAY contain attributes which SHOULD be ignored if not
      recognized.

   <!ELEMENT getetag (#PCDATA) >

14.7.  getlastmodified Property

   Name:  getlastmodified

   Namespace:  DAV:

   Purpose:  Contains the Last-Modified header returned by a GET method
      without accept headers.

   Value:  rfc1123-date (defined in section 3.3.1 of RFC2616 [6])

   Protected:  SHOULD be protected because some clients may rely on the
      value for appropriate caching behavior, or on the value of the
      Last-Modified header to which this property is linked.

   COPY/MOVE behaviour:  This property value is dependent on the last
      modified date of the destination resource, not the value of the
      property on the source resource.  Note that some server
      implementations use the file system date modified value for the
      'getlastmodified' value, and this is preserved in a MOVE even when
      the HTTP Last-Modified value SHOULD change.  Thus, clients cannot
      rely on this value for caching and SHOULD use ETags.

   Description:  Note that the last-modified date on a resource SHOULD
      only reflect changes in the body (the GET responses) of the
      resource.  A change in a property only SHOULD NOT cause the last-
      modified date to change, because clients MAY rely on the last-
      modified date to know when to overwrite the existing body.  The
      getlastmodified property MUST be defined on any DAV compliant
      resource that returns the Last- Modified header in response to a
      GET.

   Extensibility:  MAY contain attributes which SHOULD be ignored if not
      recognized.

   <!ELEMENT getlastmodified (#PCDATA) >

14.8.  lockdiscovery Property








Dusseault                 Expires May 19, 2006                 [Page 91]

Internet-Draft                 RFC2518bis                  November 2005


   Name:  lockdiscovery

   Namespace:  DAV:

   Purpose:  Describes the active locks on a resource

   Protected:  MUST be protected.  Clients change the list of locks
      through LOCK and UNLOCK, not through PROPPATCH.

   COPY/MOVE behaviour:  The value of this property depends on the lock
      state of the destination, not on the locks of the source resource.
      Recall that locks are not moved in a MOVE operation.

   Description:  The lockdiscovery property returns a listing of who has
      a lock, what type of lock he has, the timeout type and the time
      remaining on the timeout, and the associated lock token.  If there
      are no locks, but the server supports locks, the property will be
      present but contain zero 'activelock' elements.  If there is one
      or more lock, an 'activelock' element appears for each lock on the
      resource.

   Extensibility:  MAY be extended with additional child elements or
      attributes which SHOULD be ignored if not recognized.

   <!ELEMENT lockdiscovery (activelock)* >

14.8.1.  Example - Retrieving the lockdiscovery Property
























Dusseault                 Expires May 19, 2006                 [Page 92]

Internet-Draft                 RFC2518bis                  November 2005


      >>Request

        PROPFIND /container/ HTTP/1.1
        Host: www.example.com
        Content-Length: xxxx
        Content-Type: text/xml; charset="utf-8"

        <?xml version="1.0" encoding="utf-8" ?>
        <D:propfind xmlns:D='DAV:'>
         <D:prop><D:lockdiscovery/></D:prop>
        </D:propfind>

      >>Response

        HTTP/1.1 207 Multi-Status
        Content-Type: text/xml; charset="utf-8"
        Content-Length: xxxx

        <?xml version="1.0" encoding="utf-8" ?>
        <D:multistatus xmlns:D='DAV:'>
         <D:response>
           <D:href>http://www.example.com/container/</D:href>
           <D:propstat>
             <D:prop>
               <D:lockdiscovery>
                <D:activelock>
                 <D:locktype><D:write/></D:locktype>
                 <D:lockscope><D:exclusive/></D:lockscope>
                 <D:depth>0</D:depth>
                 <D:owner>Jane Smith</D:owner>
                 <D:timeout>Infinite</D:timeout>
                 <D:locktoken>
                   <D:href>urn:uuid:f81de2ad-7f3d-a1b2-4f3c
                           -00a0c91a9d76</D:href>
                 </D:locktoken>
                 <D:lockroot>
                   <D:href>http://www.example.com/container/</D:href>
                 </D:lockroot>
                 </D:activelock>
               </D:lockdiscovery>
             </D:prop>
             <D:status>HTTP/1.1 200 OK</D:status>
           </D:propstat>
         </D:response>
        </D:multistatus>

   This resource has a single exclusive write lock on it, with an
   infinite timeout.



Dusseault                 Expires May 19, 2006                 [Page 93]

Internet-Draft                 RFC2518bis                  November 2005


14.9.  resourcetype Property

   Name:  resourcetype

   Namespace:  DAV:

   Purpose:  Specifies the nature of the resource.

   Protected:  SHOULD be protected.  Resource type is generally decided
      through the operation creating the resource (MKCOL vs PUT), not by
      PROPPATCH.

   COPY/MOVE behaviour:  Generally a COPY/MOVE of a resource results in
      the same type of resource at the destination.  In a remote COPY,
      the source server SHOULD NOT attempt to set this property.

   Description:  The resourcetype property MUST be defined on all DAV
      compliant resources.  The default value is empty.

   Extensibility:  MAY be extended with any child elements or attributes
      which SHOULD be ignored if not recognized.  If the element
      contains the 'collection' child element plus additional
      unrecognized elements/attributes, it should generally be treated
      as a collection.  If the element contains no recognized child
      elements it should be treated as a non- collection WebDAV-
      compliant resource.

   Example: (fictional example to show extensibility)

       <x:resourcetype xmlns:x="DAV:">
           <x:collection/>
           <f:search-results xmlns:f="http://www.example.com/ns"/>
       </x:resourcetype>

14.10.  supportedlock Property

   Name:  supportedlock

   Namespace:  DAV:

   Purpose:  To provide a listing of the lock capabilities supported by
      the resource.

   Protected:  MUST be protected.  Servers determine what lock
      mechanisms are supported, not clients.






Dusseault                 Expires May 19, 2006                 [Page 94]

Internet-Draft                 RFC2518bis                  November 2005


   COPY/MOVE behaviour:  This property value is dependent on the kind of
      locks supported at the destination, not on the value of the
      property at the source resource.  Servers attempting to COPY to a
      destination should not attempt to set this property at the
      destination.

   Description:  The supportedlock property of a resource returns a
      listing of the combinations of scope and access types which may be
      specified in a lock request on the resource.  Note that the actual
      contents are themselves controlled by access controls so a server
      is not required to provide information the client is not
      authorized to see.

   Extensibility:  MAY be extended with any child elements or attributes
      which SHOULD be ignored if not recognized.

   <!ELEMENT supportedlock (lockentry)* >


































Dusseault                 Expires May 19, 2006                 [Page 95]

Internet-Draft                 RFC2518bis                  November 2005


14.10.1.  Example - Retrieving the supportedlock Property

      >>Request

        PROPFIND  /container/ HTTP/1.1
        Host: www.example.com
        Content-Length: xxxx
        Content-Type: text/xml; charset="utf-8"

        <?xml version="1.0" encoding="utf-8" ?>
        <D:propfind xmlns:D="DAV:">
         <D:prop><D:supportedlock/></D:prop>
        </D:propfind>

      >>Response

        HTTP/1.1 207 Multi-Status
        Content-Type: text/xml; charset="utf-8"
        Content-Length: xxxx

        <?xml version="1.0" encoding="utf-8" ?>
        <D:multistatus xmlns:D="DAV:">
         <D:response>
           <D:href>http://www.example.com/container/</D:href>
           <D:propstat>
             <D:prop>
               <D:supportedlock>
                 <D:lockentry>
                   <D:lockscope><D:exclusive/></D:lockscope>
                   <D:locktype><D:write/></D:locktype>
                 </D:lockentry>
                 <D:lockentry>
                   <D:lockscope><D:shared/></D:lockscope>
                   <D:locktype><D:write/></D:locktype>
                 </D:lockentry>
               </D:supportedlock>
             </D:prop>
             <D:status>HTTP/1.1 200 OK</D:status>
           </D:propstat>
         </D:response>
        </D:multistatus>










Dusseault                 Expires May 19, 2006                 [Page 96]

Internet-Draft                 RFC2518bis                  November 2005


15.  Precondition/postcondition XML elements

   The numerical status codes used in HTTP responses are not
   sufficiently granular or informative for all purposes.  Some
   extensions to HTTP have used the error response body along with some
   status codes in order to provide additiona machine-readable response
   detail.  The machine-readable codes are XML elements classified as
   preconditions (generally client error or failure to meet the
   conditions in order for the request to be considered) and
   postconditions (generally server error or failure to respond
   successfully to an otherwise valid request).  The precondition or
   postcondition XML element appears inside an 'error' element which is
   the root of the XML body of the response.  The 'error' root element
   or the precondition or postcondition elements MAY contain additional
   XML elements or attributes not defined in this specification.

   XML elements in error response bodies were not used in RFC2518, but
   were introduced in RFC2518bis.  Thus, use of these informative
   elements is RECOMMENDED.  Even if clients do not automatically
   recognize the error bodies they can be quite useful in
   interoperability testing and debugging.

   Name: external-entities-forbidden

   Namespace: DAV:

   Use with: 403 Forbidden

   Purpose: (precondition) -- If the server rejects a client request
      because the request body contains an external entity, the server
      SHOULD use this error.

   <!ELEMENT external-entities-forbidden EMPTY >

   Name: requesturi-must-match-lock-token

   Namespace: DAV:

   Use with: 400 Bad Request

   Purpose: (precondition) -- A request may include a Lock-Token header
      to identify a lock for the purposes of an operation such as
      refresh LOCK or UNLOCK.  However, if the Request-URI doe not fall
      within the scope of the lock identified by the token, the server
      SHOULD use this error.  The lock may have a scope that does not
      include the Request-URI, or the lock could have disappeared, or
      the token may be invalid.




Dusseault                 Expires May 19, 2006                 [Page 97]

Internet-Draft                 RFC2518bis                  November 2005


   <!ELEMENT requesturi-must-match-lock-token EMPTY >

   Name: missing-lock-token

   Namespace: DAV:

   Use with: 400 Bad Request

   Purpose: (precondition) -- If the server rejects a request because
      the request MUST have a lock token and is missing the lock token
      header or header value (e.g. on an UNLOCK request), the server
      SHOULD use this error.  The 'missing-lock-token' element MUST
      contain at least one URL of a locked resource for which a lock
      token was expected.

   <!ELEMENT missing-lock-token href* >

   Name: live-properties-not-preserved

   Namespace: DAV:

   Use with: 409 Conflict

   Purpose: (postcondition) -- The server received an otherwise-valid
      MOVE or COPY request, but cannot maintain the live properties with
      the same behavior at the destination.  It may be that the server
      only supports some live properties in some parts of the
      repository, or simply has an internal error.

   <!ELEMENT live-properties-not-preserved EMPTY >

   Name: read-only-property

   Namespace: DAV:

   Use with: 403 Forbidden

   Purpose: (precondition) -- The client attempted to set a read-only
      property in a PROPPATCH (such as 'getetag').

   <!ELEMENT read-only-property EMPTY >

   Name: propfind-infinite-depth-forbidden

   Namespace: DAV:






Dusseault                 Expires May 19, 2006                 [Page 98]

Internet-Draft                 RFC2518bis                  November 2005


   Use with: 403 Forbidden

   Purpose: (precondition) -- This server does not allow infinite-depth
      PROPFIND requests on collections.

   <!ELEMENT propfind-infinite-depth-forbidden EMPTY >

   Name: need-privileges

   Namespace: DAV:

   Use with: 403 Forbidden

   Purpose: (precondition) -- The currently authenticated user simply
      does not have the privileges required to do the requested
      operation (e.g.  UNLOCK a lock created by someone else).

   <!ELEMENT need-privileges EMPTY >

   Name: missing-lock-token

   Namespace: DAV:

   Use with: 423 Locked

   Purpose: (precondition) -- The request could not succeed because a
      lock token should have been provided.  This element, if present,
      MUST contain the URL of a locked resource that prevented the
      request.  In cases of MOVE, COPY and DELETE where collection locks
      are involved, it can be difficult for the client to find out which
      locked resource made the request fail -- but the server is only
      resonsible for returning one such locked resource.  The server MAY
      return every locked resource that prevented the request from
      succeeding if it knows them all.

   <!ELEMENT missing-lock-token (href+) >















Dusseault                 Expires May 19, 2006                 [Page 99]

Internet-Draft                 RFC2518bis                  November 2005


16.  Instructions for Processing XML in DAV

   All DAV compliant resources MUST ignore any unknown XML element and
   all its children encountered while processing a DAV method that uses
   XML as its command language.

   This restriction also applies to the processing, by clients, of DAV
   property values where unknown XML elements SHOULD be ignored unless
   the property's schema declares otherwise.

   This restriction does not apply to setting dead DAV properties on the
   server where the server MUST record unknown XML elements.

   Additionally, this restriction does not apply to the use of XML where
   XML happens to be the content type of the entity body, for example,
   when used as the body of a PUT.

   Since XML can be transported as text/xml or application/xml, a DAV
   server MUST accept DAV method requests with XML parameters
   transported as either text/xml or application/xml, and a DAV client
   MUST accept XML responses using either text/xml or application/xml.

   XML DTD fragments are included for all the XML elements defined in
   this specification.  However, legal XML may not be valid according to
   any DTD due to namespace usage and extension rules, so the DTD is
   only informational.  A recipient of a WebDAV message with an XML body
   MUST NOT validate the XML document according to any hard-coded or
   dynamically-declared DTD.























Dusseault                 Expires May 19, 2006                [Page 100]

Internet-Draft                 RFC2518bis                  November 2005


17.  DAV Compliance Classes

   A DAV compliant resource can advertise several classes of compliance.
   A client can discover the compliance classes of a resource by
   executing OPTIONS on the resource, and examining the "DAV" header
   which is returned.  Note particularly that resources are spoken of as
   being compliant, rather than servers.  That is because theoretically
   some resources on a server could support different feature sets.
   E.g. a server could have a sub-repository where an advanced feature
   like server was supported, even if that feature was not supported on
   all servers.

   Since this document describes extensions to the HTTP/1.1 protocol,
   minimally all DAV compliant resources, clients, and proxies MUST be
   compliant with RFC2616 [6].

   A resource that is class 2 compliant must also be class 1 compliant,
   and a resource that is compliant with "bis" must also be class 1
   compliant.

17.1.  Class 1

   A class 1 compliant resource MUST meet all "MUST" requirements in all
   sections of this document.

   Class 1 compliant resources MUST return, at minimum, the value "1" in
   the DAV header on all responses to the OPTIONS method.

17.2.  Class 2

   A class 2 compliant resource MUST meet all class 1 requirements and
   support the LOCK method, the supportedlock property, the
   lockdiscovery property, the Time-Out response header and the Lock-
   Token request header.  A class "2" compliant resource SHOULD also
   support the Time-Out request header and the owner XML element.

   Class 2 compliant resources MUST return, at minimum, the values "1"
   and "2" in the DAV header on all responses to the OPTIONS method.

17.3.  Class 'bis'

   A resource can explicitly advertise its support for the revisions to
   RFC2518 made in this document.  In particular, this allows clients to
   use the Force-Authentication header on requests.  Class 1 must be
   supported as well.  Class 2 MAY be supported.

   A resource that supports bis MUST support:




Dusseault                 Expires May 19, 2006                [Page 101]

Internet-Draft                 RFC2518bis                  November 2005


   o  the Force-Authentication header.

   o  Any behavior that it supports, in the manner specified in this
      document, rather than in the manner specified in RFC2518, for all
      client requests.  A server MAY use an older behavior for specific
      clients that are discovered to have interoperability problems with
      the requirements of this specification, but MUST NOT use an older
      behavior indiscriminately.

   Example:

            DAV: 1, bis







































Dusseault                 Expires May 19, 2006                [Page 102]

Internet-Draft                 RFC2518bis                  November 2005


18.  Internationalization Considerations

   In the realm of internationalization, this specification complies
   with the IETF Character Set Policy RFC2277 [6].  In this
   specification, human-readable fields can be found either in the value
   of a property, or in an error message returned in a response entity
   body.  In both cases, the human-readable content is encoded using
   XML, which has explicit provisions for character set tagging and
   encoding, and requires that XML processors read XML elements encoded,
   at minimum, using the UTF-8 RFC2279 [4] and UTF-16 encodings of the
   ISO 10646 multilingual plane.  XML examples in this specification
   demonstrate use of the charset parameter of the Content-Type header,
   as defined in RFC2376 [13], as well as the XML declarations which
   provide charset identification information for MIME and XML
   processors.

   XML also provides a language tagging capability for specifying the
   language of the contents of a particular XML element.  The "xml:lang"
   attribute appears on an XML element to identify the language of its
   content and attributes.  See XML [11] for definitions of values and
   scoping.

   WebDAV applications MUST support the character set tagging, character
   set encoding, and the language tagging functionality of the XML
   specification.  Implementors of WebDAV applications are strongly
   encouraged to read "XML Media Types" RFC2376 [13] for instruction on
   which MIME media type to use for XML transport, and on use of the
   charset parameter of the Content-Type header.

   Names used within this specification fall into four categories: names
   of protocol elements such as methods and headers, names of XML
   elements, names of properties, and names of conditions.  Naming of
   protocol elements follows the precedent of HTTP, using English names
   encoded in USASCII for methods and headers.  Since these protocol
   elements are not visible to users, and are simply long token
   identifiers, they do not need to support multiple languages.
   Similarly, the names of XML elements used in this specification are
   not visible to the user and hence do not need to support multiple
   languages.

   WebDAV property names are qualified XML names (pairs of XML namespace
   name and local name).  Although some applications (e.g., a generic
   property viewer) will display property names directly to their users,
   it is expected that the typical application will use a fixed set of
   properties, and will provide a mapping from the property name and
   namespace to a human-readable field when displaying the property name
   to a user.  It is only in the case where the set of properties is not
   known ahead of time that an application need display a property name



Dusseault                 Expires May 19, 2006                [Page 103]

Internet-Draft                 RFC2518bis                  November 2005


   to a user.  We recommend that applications provide human-readable
   property names wherever feasible.

   For error reporting, we follow the convention of HTTP/1.1 status
   codes, including with each status code a short, English description
   of the code (e.g., 423 (Locked)).  While the possibility exists that
   a poorly crafted user agent would display this message to a user,
   internationalized applications will ignore this message, and display
   an appropriate message in the user's language and character set.

   Since interoperation of clients and servers does not require locale
   information, this specification does not specify any mechanism for
   transmission of this information.






































Dusseault                 Expires May 19, 2006                [Page 104]

Internet-Draft                 RFC2518bis                  November 2005


19.  Security Considerations

   This section is provided to detail issues concerning security
   implications of which WebDAV applications need to be aware.

   All of the security considerations of HTTP/1.1 (discussed in RFC2616
   [6]) and XML (discussed in RFC2376 [13]) also apply to WebDAV.  In
   addition, the security risks inherent in remote authoring require
   stronger authentication technology, introduce several new privacy
   concerns, and may increase the hazards from poor server design.
   These issues are detailed below.

19.1.  Authentication of Clients

   Due to their emphasis on authoring, WebDAV servers need to use
   authentication technology to protect not just access to a network
   resource, but the integrity of the resource as well.  Furthermore,
   the introduction of locking functionality requires support for
   authentication.

   A password sent in the clear over an insecure channel is an
   inadequate means for protecting the accessibility and integrity of a
   resource as the password may be intercepted.  Since Basic
   authentication for HTTP/1.1 performs essentially clear text
   transmission of a password, Basic authentication MUST NOT be used to
   authenticate a WebDAV client to a server unless the connection is
   secure.  Furthermore, a WebDAV server MUST NOT send Basic
   authentication credentials in a WWW-Authenticate header unless the
   connection is secure.  Examples of secure connections include a
   Transport Layer Security (TLS) connection employing a strong cipher
   suite with mutual authentication of client and server, or a
   connection over a network which is physically secure, for example, an
   isolated network in a building with restricted access.

   WebDAV applications MUST support the Digest authentication scheme
   RFC2069 [1].  Since Digest authentication verifies that both parties
   to a communication know a shared secret, a password, without having
   to send that secret in the clear, Digest authentication avoids the
   security problems inherent in Basic authentication while providing a
   level of authentication which is useful in a wide range of scenarios.

19.2.  Denial of Service

   Denial of service attacks are of special concern to WebDAV servers.
   WebDAV plus HTTP enables denial of service attacks on every part of a
   system's resources.

   The underlying storage can be attacked by PUTting extremely large



Dusseault                 Expires May 19, 2006                [Page 105]

Internet-Draft                 RFC2518bis                  November 2005


   files.

   Asking for recursive operations on large collections can attack
   processing time.

   Making multiple pipelined requests on multiple connections can attack
   network connections.

   WebDAV servers need to be aware of the possibility of a denial of
   service attack at all levels.

19.3.  Security through Obscurity

   WebDAV provides, through the PROPFIND method, a mechanism for listing
   the member resources of a collection.  This greatly diminishes the
   effectiveness of security or privacy techniques that rely only on the
   difficulty of discovering the names of network resources.  Users of
   WebDAV servers are encouraged to use access control techniques to
   prevent unwanted access to resources, rather than depending on the
   relative obscurity of their resource names.

19.4.  Privacy Issues Connected to Locks

   When submitting a lock request a user agent may also submit an owner
   XML field giving contact information for the person taking out the
   lock (for those cases where a person, rather than a robot, is taking
   out the lock).  This contact information is stored in a lockdiscovery
   property on the resource, and can be used by other collaborators to
   begin negotiation over access to the resource.  However, in many
   cases this contact information can be very private, and should not be
   widely disseminated.  Servers SHOULD limit read access to the
   lockdiscovery property as appropriate.  Furthermore, user agents
   SHOULD provide control over whether contact information is sent at
   all, and if contact information is sent, control over exactly what
   information is sent.

19.5.  Privacy Issues Connected to Properties

   Since property values are typically used to hold information such as
   the author of a document, there is the possibility that privacy
   concerns could arise stemming from widespread access to a resource's
   property data.  To reduce the risk of inadvertent release of private
   information via properties, servers are encouraged to develop access
   control mechanisms that separate read access to the resource body and
   read access to the resource's properties.  This allows a user to
   control the dissemination of their property data without overly
   restricting access to the resource's contents.




Dusseault                 Expires May 19, 2006                [Page 106]

Internet-Draft                 RFC2518bis                  November 2005


19.6.  Implications of XML External Entities

   XML supports a facility known as "external entities", defined in
   section 4.2.2 of XML [11], which instruct an XML processor to
   retrieve and include additional XML.  An external XML entity can be
   used to append or modify the document type declaration (DTD)
   associated with an XML document.  An external XML entity can also be
   used to include XML within the content of an XML document.  For non-
   validating XML, such as the XML used in this specification, including
   an external XML entity is not required by XML [11].  However, XML
   [11] does state that an XML processor may, at its discretion, include
   the external XML entity.

   External XML entities have no inherent trustworthiness and are
   subject to all the attacks that are endemic to any HTTP GET request.
   Furthermore, it is possible for an external XML entity to modify the
   DTD, and hence affect the final form of an XML document, in the worst
   case significantly modifying its semantics, or exposing the XML
   processor to the security risks discussed in RFC2376 [13].
   Therefore, implementers must be aware that external XML entities
   should be treated as untrustworthy.  If a server implementor chooses
   not to handle external XML entities, it SHOULD respond to requests
   containing external entities with the precondition defined above
   (external-entities-forbidden).

   There is also the scalability risk that would accompany a widely
   deployed application which made use of external XML entities.  In
   this situation, it is possible that there would be significant
   numbers of requests for one external XML entity, potentially
   overloading any server which fields requests for the resource
   containing the external XML entity.

19.7.  Risks Connected with Lock Tokens

   This specification requires the use of A Universally  Unique
   Identifier (UUID) URN Namespace [9] for lock tokens, in order to
   guarantee their uniqueness across space and time.  The security
   considerations for UUIDs do not apply because WebDAV does not assume
   that lock tokens are supposed to be hard to guess or require
   integrity.  In addition, UUIDs MAY contain a IEEE 802 node ID,
   usually the host address.  Since a WebDAV server will issue many
   locks over its lifetime, the use of node IDs might cause the WebDAV
   server to reveal its IEEE 802 address.  Several risks are related to
   this:

   o  It is possible to track the movement of hardware from subnet to
      subnet.




Dusseault                 Expires May 19, 2006                [Page 107]

Internet-Draft                 RFC2518bis                  November 2005


   o  It may be possible to identify the manufacturer of the hardware
      running a WebDAV server.

   o  It may be possible to determine the number of each type of
      computer running WebDAV.

19.8.  Hosting malicious scripts executed on client machines

   HTTP has the ability to host scripts which are executed on client
   machines.  These scripts can be used to read another user's cookies
   and therefore may provide an attacker the ability to use another
   user's session, assume their identity temporarily and gain access to
   their resources.  Other attacks are also possible with client-
   executed scripts.

   WebDAV may worsen this situation only by making it easier for a Web
   server to host content provided by many different authors (making it
   harder to trust the content providers) and to host content with
   restricted access alongside public pages (see particularly RFC3744).

   HTTP servers may mitigate some of these threats by filtering content
   in areas where many authors contribute pages -- the server could, for
   example, remove script from HTML pages.

   This vulnerability should provide yet another reason for server
   implementors and administrators not to replace authentication
   mechanisms with cookie-based session tokens if there's any sensitive
   information relying on the authenticated identity.

   HTTP and WebDAV client implementors might consider locking down the
   use of scripts and cookies based on these considerations.




















Dusseault                 Expires May 19, 2006                [Page 108]

Internet-Draft                 RFC2518bis                  November 2005


20.  IANA Considerations

   This specification defines two URI schemes:

      the "opaquelocktoken" scheme defined in Appendix C, and

      the "DAV" URI scheme, which historically was used in RFC2518 to
      disambiguate WebDAV property and XML element names and which
      continues to be used for that purpose in this specification and
      others extending WebDAV.  Creation of identifiers in the "DAV:"
      namespace is controlled by the IETF.

   XML namespaces disambiguate WebDAV property names and XML elements.
   Any WebDAV user or application can define a new namespace in order to
   create custom properties or extend WebDAV XML syntax.  IANA does not
   need to manage such namespaces, property names or element names.



































Dusseault                 Expires May 19, 2006                [Page 109]

Internet-Draft                 RFC2518bis                  November 2005


21.  Acknowledgements

   A specification such as this thrives on piercing critical review and
   withers from apathetic neglect.  The authors gratefully acknowledge
   the contributions of the following people, whose insights were so
   valuable at every stage of our work.

   Contributors to RFC2518

   Terry Allen, Harald Alvestrand, Jim Amsden, Becky Anderson, Alan
   Babich, Sanford Barr, Dylan Barrell, Bernard Chester, Tim Berners-
   Lee, Dan Connolly, Jim Cunningham, Ron Daniel, Jr., Jim Davis, Keith
   Dawson, Mark Day, Brian Deen, Martin Duerst, David Durand, Lee
   Farrell, Chuck Fay, Wesley Felter, Roy Fielding, Mark Fisher, Alan
   Freier, George Florentine, Jim Gettys, Phill Hallam-Baker, Dennis
   Hamilton, Steve Henning, Mead Himelstein, Alex Hopmann, Andre van der
   Hoek, Ben Laurie, Paul Leach, Ora Lassila, Karen MacArthur, Steven
   Martin, Larry Masinter, Michael Mealling, Keith Moore, Thomas Narten,
   Henrik Nielsen, Kenji Ota, Bob Parker, Glenn Peterson, Jon Radoff,
   Saveen Reddy, Henry Sanders, Christopher Seiwald, Judith Slein, Mike
   Spreitzer, Einar Stefferud, Greg Stein, Ralph Swick, Kenji Takahashi,
   Richard N. Taylor, Robert Thau, John Turner, Sankar Virdhagriswaran,
   Fabio Vitali, Gregory Woodhouse, and Lauren Wood.

   Two from this list deserve special mention.  The contributions by
   Larry Masinter have been invaluable, both in helping the formation of
   the working group and in patiently coaching the authors along the
   way.  In so many ways he has set high standards we have toiled to
   meet.  The contributions of Judith Slein in clarifying the
   requirements, and in patiently reviewing draft after draft, both
   improved this specification and expanded our minds on document
   management.

   We would also like to thank John Turner for developing the XML DTD.

   The authors of RFC2518 were Yaron Goland, Jim Whitehead, A. Faizi,
   Steve Carter and D. Jensen.  Although their names had to be removed
   due to IETF author count restrictions they can take credit for the
   majority of the design of WebDAV.

   Additional Contributors to This Specification

   Valuable contributions to RFC2518 bis came from some already named.
   New contributors must also be gratefully acknowledged.  Julian
   Reschke, Geoff Clemm, Joel Soderberg, and Dan Brotsky hashed out
   specific text on the list or in meetings.  Ilya Kirnos supplied text
   for Force-Authentication header.  Joe Hildebrand contributed as co-
   chair.  Barry Lind described an additional security consideration.



Dusseault                 Expires May 19, 2006                [Page 110]

Internet-Draft                 RFC2518bis                  November 2005


   Jason Crawford tracked issue status for this document for a period of
   years, followed by Elias Sinderson.

21.1.  Previous Authors' Addresses

   Editors of RFC2518

   Y. Y. Goland Microsoft Corporation One Microsoft Way Redmond, WA
   98052-6399 Email: yarong@microsoft.com

   E. J. Whitehead, Jr. Dept.  Of Information and Computer Science
   University of California, Irvine Irvine, CA 92697-3425 Email:
   ejw@ics.uci.edu

   A. Faizi Netscape 685 East Middlefield Road Mountain View, CA 94043
   Email: asad@netscape.com

   S. R. Carter Novell 1555 N. Technology Way M/S ORM F111 Orem, UT
   84097-2399 Email: srcarter@novell.com

   D. Jensen Novell 1555 N. Technology Way M/S ORM F111 Orem, UT 84097-
   2399 Email: dcjensen@novell.com





























Dusseault                 Expires May 19, 2006                [Page 111]

Internet-Draft                 RFC2518bis                  November 2005


22.  References

22.1.  Normative References

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

   [2]   Bradner, S., "Key words for use in RFCs to Indicate Requirement
         Levels", BCP 14, RFC 2119, March 1997.

   [3]   Alvestrand, H., "IETF Policy on Character Sets and Languages",
         BCP 18, RFC 2277, January 1998.

   [4]   Yergeau, F., "UTF-8, a transformation format of ISO 10646",
         RFC 2279, January 1998.

   [5]   Goland, Y., Whitehead, E., Faizi, A., Carter, S., and D.
         Jensen, "HTTP Extensions for Distributed Authoring -- WEBDAV",
         RFC 2518, February 1999.

   [6]   Fielding, R., Gettys, J., Mogul, J., Frystyk, H., Masinter, L.,
         Leach, P., and T. Berners-Lee, "Hypertext Transfer Protocol --
         HTTP/1.1", RFC 2616, June 1999.

   [7]   Klyne, G. and C. Newman, "Date and Time on the Internet:
         Timestamps", RFC 3339, July 2002.

   [8]   Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
         Resource Identifier (URI): Generic Syntax", STD 66, RFC 3986,
         January 2005.

   [9]   Leach, P., Mealling, M., and R. Salz, "A Universally Unique
         IDentifier (UUID) URN Namespace", RFC 4122, July 2005.

   [10]  Hollander, D., Bray, T., and A. Layman, "Namespaces in XML",
         W3C REC REC-xml-names-19990114, January 1999.

   [11]  Paoli, J., Sperberg-McQueen, C., Bray, T., and E. Maler,
         "Extensible Markup Language (XML) 1.0 (Second Edition)", W3C
         FirstEdition REC-xml-20001006, October 2000.

22.2.  Informational References

   [12]  Slein, J., Vitali, F., Whitehead, E., and D. Durand,
         "Requirements for a Distributed Authoring and Versioning
         Protocol for the World Wide Web", RFC 2291, February 1998.




Dusseault                 Expires May 19, 2006                [Page 112]

Internet-Draft                 RFC2518bis                  November 2005


   [13]  Whitehead, E. and M. Makoto, "XML Media Types", RFC 2376,
         July 1998.

   [14]  Clemm, G., Amsden, J., Ellison, T., Kaler, C., and J.
         Whitehead, "Versioning Extensions to WebDAV (Web Distributed
         Authoring and Versioning)", RFC 3253, March 2002.

   [15]  Clemm, G., Reschke, J., Sedlar, E., and J. Whitehead, "Web
         Distributed Authoring and Versioning (WebDAV) Access Control
         Protocol", RFC 3744, May 2004.









































Dusseault                 Expires May 19, 2006                [Page 113]

Internet-Draft                 RFC2518bis                  November 2005


Appendix A.  Notes on Processing XML Elements

A.1.  Notes on Empty XML Elements

   XML supports two mechanisms for indicating that an XML element does
   not have any content.  The first is to declare an XML element of the
   form <A></A>.  The second is to declare an XML element of the form
   <A/>.  The two XML elements are semantically identical.

A.2.  Notes on Illegal XML Processing

   XML is a flexible data format that makes it easy to submit data that
   appears legal but in fact is not.  The philosophy of "Be flexible in
   what you accept and strict in what you send" still applies, but it
   must not be applied inappropriately.  XML is extremely flexible in
   dealing with issues of white space, element ordering, inserting new
   elements, etc.  This flexibility does not require extension,
   especially not in the area of the meaning of elements.

   There is no kindness in accepting illegal combinations of XML
   elements.  At best it will cause an unwanted result and at worst it
   can cause real damage.

A.3.  Example - XML Syntax Error

   The following request body for a PROPFIND method is illegal.

      <?xml version="1.0" encoding="utf-8" ?>
      <D:propfind xmlns:D="DAV:">
       <D:allprop/>
       <D:propname/>
      </D:propfind>

   The definition of the propfind element only allows for the allprop or
   the propname element, not both.  Thus the above is an error and must
   be responded to with a 400 (Bad Request).

   Imagine, however, that a server wanted to be "kind" and decided to
   pick the allprop element as the true element and respond to it.  A
   client running over a bandwidth limited line who intended to execute
   a propname would be in for a big surprise if the server treated the
   command as an allprop.

   Additionally, if a server were lenient and decided to reply to this
   request, the results would vary randomly from server to server, with
   some servers executing the allprop directive, and others executing
   the propname directive.  This reduces interoperability rather than
   increasing it.



Dusseault                 Expires May 19, 2006                [Page 114]

Internet-Draft                 RFC2518bis                  November 2005


A.4.  Example - Unknown XML Element

   The previous example was illegal because it contained two elements
   that were explicitly banned from appearing together in the propfind
   element.  However, XML is an extensible language, so one can imagine
   new elements being defined for use with propfind.  Below is the
   request body of a PROPFIND and, like the previous example, must be
   rejected with a 400 (Bad Request) by a server that does not
   understand the expired-props element.

      <?xml version="1.0" encoding="utf-8" ?>
      <D:propfind xmlns:D="DAV:"
      xmlns:E="http://www.example.com/standards/props/">
       <E:expired-props/>
      </D:propfind>

   To understand why a 400 (Bad Request) is returned let us look at the
   request body as the server unfamiliar with expired-props sees it.

      <?xml version="1.0" encoding="utf-8" ?>
      <D:propfind xmlns:D="DAV:"
                  xmlns:E="http://www.example.com/standards/props/">
      </D:propfind>

   As the server does not understand the expired-props element,
   according to the WebDAV-specific XML processing rules specified in
   Section 16, it must ignore it.  Thus the server sees an empty
   propfind, which by the definition of the propfind element is illegal.

   Please note that had the extension been additive it would not
   necessarily have resulted in a 400 (Bad Request).  For example,
   imagine the following request body for a PROPFIND:


      <?xml version="1.0" encoding="utf-8" ?>
      <D:propfind xmlns:D="DAV:"
                  xmlns:E="http://www.example.com/standards/props/">
       <D:propname/>
       <E:leave-out>*boss*</E:leave-out>
      </D:propfind>

   The previous example contains the fictitious element leave-out.  Its
   purpose is to prevent the return of any property whose name matches
   the submitted pattern.  If the previous example were submitted to a
   server unfamiliar with leave-out, the only result would be that the
   leave-out element would be ignored and a propname would be executed.





Dusseault                 Expires May 19, 2006                [Page 115]

Internet-Draft                 RFC2518bis                  November 2005


Appendix B.  Notes on HTTP Client Compatibility

   The PUT and DELETE methods are defined in HTTP and thus may be used
   by HTTP clients, but the responses to PUT and DELETE have been
   extended in this specification, so some special consideration on
   backward compatibility is worthwhile.

   First, if a PUT or DELETE request includes a header defined in this
   specification (Depth or If), the server can assume the request comes
   from a WebDAV-compatible client.  The server may even be able to
   track a number of requests across a session and know that a client is
   a WebDAV client.  However, this kind of detection may not be
   necessary.

   Since any HTTP client ought to handle unrecognized 400-level and 500-
   level status codes as errors, the following new status codes should
   not present any issues: 422, 423 and 507. 424 is also a new status
   code but it appears only in the body of a Multistatus response.  So,
   for example, if a HTTP client attempted to PUT or DELETE a locked
   resource, the 423 Locked response ought to result in a generic error
   presented to the user.

   The 102 Processing response code is new, and indicates that the
   client may wish to extend its normal timeout period.  However, the
   choice to extend the timeout period is entirely optional, and thus a
   HTTP client receiving a 102 Processing status response may time out
   anyway, with no avoidable adverse effects.

   The 207 Multistatus response is interesting because a HTTP client
   issuing a DELETE request to a collection might interpret a 207
   response as a success, even though it does not realize the resource
   is a collection and cannot understand that the DELETE operation might
   have been a complete or partial failure.  Thus, a server MAY choose
   to treat a DELETE of a collection as an atomic operation, and use
   either 204 No Content in case of success, or some appropriate error
   response (400 or 500 level) depending on what the error was.  This
   approach would maximize backward compatibility.  However, since
   interoperability tests and working group discussions have not turned
   up any instances of HTTP clients issuing a DELETE request against a
   WebDAV collection, this concern may be more theoretical than
   practical.  Thus, servers MAY instead choose to treat any such DELETE
   request as a WebDAV request, and send a 207 Multistatus containing
   more detail about what resources could not be deleted.








Dusseault                 Expires May 19, 2006                [Page 116]

Internet-Draft                 RFC2518bis                  November 2005


Appendix C.  The opaquelocktoken scheme and URIs

   The 'opaquelocktoken' URI scheme was defined in RFC2518 (and
   registered by IANA) in order to create syntactically correct and
   easy-to-generate URIs out of UUIDs, intended to be used as lock
   tokens and to be unique across all resources for all time.  This
   scheme has been obsoleted by [9], but is re-defined here for clarity.

   A server MAY generate one ore more UUIDs to use with the
   'opaquelocktoken' scheme as lock tokens.  A server MAY reuse a UUID
   with extension characters added.  If the server does this then the
   algorithm generating the extensions MUST guarantee that the same
   extension will never be used twice with the associated UUID.

   OpaqueLockToken-URI = "opaquelocktoken:" UUID [Extension] ; The UUID
   production is the string representation of a UUID.  Note that white
   space (LWS) is not allowed between elements of this production.

   Extension = path ; path is defined in section 3.3 of RFC3986 [8]
































Dusseault                 Expires May 19, 2006                [Page 117]

Internet-Draft                 RFC2518bis                  November 2005


Appendix D.  Changes

D.1.  Summary of changes from RFC2518

   This section describes changes that are likely to result in
   implementation changes due to tightened requirements or changed
   behavior.  A more complete list of changes has been published in a
   separate document.

D.1.1.  Changes Notable to Server Implementors

   Tightened requirements for storing property values (Section 4.4) when
   "xml:lang" appears and also when values are XML fragments
   (specifically on preserving prefixes, namespaces and whitespace.)

   Several tightened requirements for general response  handling
   (Section 8.1), including response bodies for use with errors, use of
   Date header, ETag and Location header.

   Tightened requirements for URL construction in PROPFIND (Section 8.2)
   responses.

   Tightened requirements for checking identity of lock  owners
   (Section 7.1) during operations affected by locks.

   Tightened requirements for copying properties (Section 8.9.2) and
   moving properties (Section 8.10.1).

   Tightened requirements on preserving owner field in locks
   (Section 8.11).  Added "lockroot" element to lockdiscovery
   information.

   New value for "DAV:" header (Section 9.1) to advertise support for
   this specification.

   Tightened requirement for "Destination:" header (Section 9.3) to work
   with path values

   New "Force-Authentication:" (Section 9.4) header added.

   Several changes for "If:" header (Section 9.5), including requirement
   to accept commas and "DAV:no-lock" state token.

   Support for UTF-16 now required (ref (Section 18)).

   Removed definition of "source" property and special handling for
   dynamic resources




Dusseault                 Expires May 19, 2006                [Page 118]

Internet-Draft                 RFC2518bis                  November 2005


   Replaced lock-null resources with simpler locked empty resources.
   (Section 7.6)

   Encouraged servers to change ETags (Section 8.1.4) only when body of
   resource changes.

D.1.2.  Changes Notable to Client Implementors

   Tightened requirements for supporting WebDAV collections
   (Section 5.2) within resources that do not support WebDAV (e.g.
   servlet containers).

   Redefined 'allprop' PROPFIND requests so that the server does not
   have to return all properties.

   Required to handle empty multistatus responses in PROPFIND  responses
   (Section 8.2)

   No more "propertybehavior" specification allowed in MOVE and COPY
   requests

   Support for UTF-16 now required (ref (Section 18)).

   Removed definition of "source" property and special handling for
   dynamic resources.

D.2.  Changes from -05 to -06

   Specified that a successful LOCK request to an unmapped URL creates a
   new, empty locked resource.

   Resolved UNLOCK_NEEDS_IF_HEADER by clarifying that only Lock-Token
   header is needed on UNLOCK.

   Added Section 15 on preconditions and postconditions and defined a
   number of preconditions and postconditions.  The 'missing-lock-token'
   precondition resolves the REPORT_OTHER_RESOURCE_LOCKED issue.

   Added example of matching lock token to URI in the case of a
   collection lock in the If header section.

   Removed ability for Destination header to take "abs_path" in order to
   keep consistent with other places where client provides URLs (If
   header, href element in request body)

   Clarified the href element - that it generally contains HTTP URIs but
   not always.




Dusseault                 Expires May 19, 2006                [Page 119]

Internet-Draft                 RFC2518bis                  November 2005


   Attempted to fix the BNF describing the If header to allow commas

   Clarified presence of Depth header on LOCK refresh requests.

D.3.  Changes in -07

   Added text to "COPY and the Overwrite Header" section to resolve
   issue OVERWRITE_DELETE_ALL_TOO_STRONG.

   Added text to "HTTP URL Namespace Model" section to provide more
   clarification and examples on what consistency means and what is not
   required, to resolve issue CONSISTENCY.

   Resolve DEFINE_PRINCIPAL by importing definition of principal from
   RFC3744.

   Resolve INTEROP_DELETE_AND_MULTISTATUS by adding appendix 3
   discussing backward-compatibility concerns.

   Resolve DATE_FORMAT_GETLASTMODIFIED by allowing only rfc1123-date,
   not HTTP-date for getlastmodified.

   Resolve COPY_INTO_YOURSELF_CLARIFY by adding sentence to first para.
   of COPY section.

   Confirm that WHEN_TO_MULTISTATUS_FOR_DELETE_1 and
   WHEN_TO_MULTISTATUS_FOR_DELETE_2 are resolved and tweak language in
   DELETE section slightly to be clearly consistent.

   More text clarifications to deal with several of the issues in
   LOCK_ISSUES.  This may not completely resolve that set but we need
   feedback from the originator of the issues at this point.

   Resolved COPY_INTO_YOURSELF_CLARIFY with new sentence in Copy For
   Collections section.

   Double checked that LEVEL_OR_CLASS is resolved by using class, not
   level.

   Further work to resolve IF_AND_AUTH and LOCK_SEMANTICS, clarifying
   text on using locks and being authenticated.

   Added notes on use of 503 status response to resolve issue
   PROPFIND_INFINITY

   Removed section on other uses of Metadata (and associated references)

   Added reference to RFC4122 for lock tokens and removed section on



Dusseault                 Expires May 19, 2006                [Page 120]

Internet-Draft                 RFC2518bis                  November 2005


   generating UUIDs

   Explained that even with language variation, a property has only one
   value (section 4.5).

   Added section on lock owner (7.1) and what to do if lock requested by
   unauthenticated user

   Removed section 4.2 -- justification on why to have metadata, not
   needed now

   Removed paragraph in section 5.2 about collections with resource type
   "DAV:collection" but which are non-WebDAV compliant -- not
   implemented.

D.4.  Changes in -08

   Added security considerations section on scripts and cookie sessions,
   suggested by Barry Lind

   Clarified which error codes are defined and undefined in MultiStatus

   Moved opaquelocktoken definition to an appendix and refer to RFC4122
   for use of 'urn:uuid:' URI scheme; fix all lock token examples to use
   this.

   Multi-status responses contain URLs which MUST either be absolute
   (and begin with the Request-URI or MUST be relative with new
   limitations. (bug 12)

   Moved status code sections before example sections within PROPFIND
   section for section ordering consistency.

   Clarified use of Location header with Multi-Status

   Bugzilla issue resolutions: bugs 9, 12, 14, 19, 20, 29, 30, 34, 36,
   102 and 172.














Dusseault                 Expires May 19, 2006                [Page 121]

Internet-Draft                 RFC2518bis                  November 2005


Author's Address

   Lisa Dusseault
   Open Source Application Foundation
   2064 Edgewood Dr.
   Palo Alto, CA  94303
   US

   Email: lisa@osafoundation.org










































Dusseault                 Expires May 19, 2006                [Page 122]

Internet-Draft                 RFC2518bis                  November 2005


Intellectual Property Statement

   The IETF takes no position regarding the validity or scope of any
   Intellectual Property Rights or other rights that might be claimed to
   pertain to the implementation or use of the technology described in
   this document or the extent to which any license under such rights
   might or might not be available; nor does it represent that it has
   made any independent effort to identify any such rights.  Information
   on the procedures with respect to rights in RFC documents can be
   found in BCP 78 and BCP 79.

   Copies of IPR disclosures made to the IETF Secretariat and any
   assurances of licenses to be made available, or the result of an
   attempt made to obtain a general license or permission for the use of
   such proprietary rights by implementers or users of this
   specification can be obtained from the IETF on-line IPR repository at
   http://www.ietf.org/ipr.

   The IETF invites any interested party to bring to its attention any
   copyrights, patents or patent applications, or other proprietary
   rights that may cover technology that may be required to implement
   this standard.  Please address the information to the IETF at
   ietf-ipr@ietf.org.


Disclaimer of Validity

   This document and the information contained herein are provided on an
   "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS
   OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET
   ENGINEERING TASK FORCE DISCLAIM 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.


Copyright Statement

   Copyright (C) The Internet Society (2005).  This document is subject
   to the rights, licenses and restrictions contained in BCP 78, and
   except as set forth therein, the authors retain all their rights.


Acknowledgment

   Funding for the RFC Editor function is currently provided by the
   Internet Society.




Dusseault                 Expires May 19, 2006                [Page 123]


Html markup produced by rfcmarkup 1.109, available from https://tools.ietf.org/tools/rfcmarkup/