Network Working GroupInternet Engineering Task Force (IETF) K. MurchisonInternet-DraftRequest for Comments: 8144 CMU Updates: 7240(if approved) January 13,April 2017Intended status:Category: Standards TrackExpires: July 17, 2017ISSN: 2070-1721 Use of the Prefer Header Field in Web Distributed Authoring and Versioning (WebDAV)draft-murchison-webdav-prefer-14Abstract This document definesan update tohow theHTTPPrefer header field[RFC7240] to specify how it(RFC 7240) can be used by aWebDAVWeb Distributed Authoring and Versioning (WebDAV) client to request that certain behaviors be employed by a server while constructing a response to a request. Furthermore, it defines the new"depth- noroot""depth-noroot" preference.Editorial Note (To be removed by RFC Editor before publication) Please send comments to the Web Distributed Authoring and Versioning (WebDAV) mailing list at <mailto:w3c-dist-auth@w3.org> [1], which may be joined by sending a message with subject "subscribe" to <mailto:w3c-dist-auth-request@w3.org> [2].Thismailing list is archived at <http://lists.w3.org/Archives/Public/w3c-dist-auth/> [3].document updates RFC 7240. Status of This Memo ThisInternet-Draftissubmitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documentsan Internet Standards Track document. This document is a product of the Internet Engineering Task Force (IETF).Note that other groups may also distribute working documents as Internet-Drafts. The listIt represents the consensus ofcurrent Internet- Drafts is at http://datatracker.ietf.org/drafts/current/. Internet-Drafts are draft documents validthe IETF community. It has received public review and has been approved fora maximumpublication by the Internet Engineering Steering Group (IESG). Further information on Internet Standards is available in Section 2 of RFC 7841. Information about the current status ofsix monthsthis document, any errata, and how to provide feedback on it may beupdated, replaced, or obsoleted by other documentsobtained atany time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." This Internet-Draft will expire on July 17, 2017.http://www.rfc-editor.org/info/rfc8144. Copyright Notice Copyright (c) 2017 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . .32 1.1. Notational Conventions . . . . . . . . . . . . . . . . . 3 2. Reducing WebDAV Response Verbosity with "return=minimal" . .. . . . . . . . . . . . . . . . . . . .3 2.1. Minimal PROPFIND and REPORT Responses . . . . . . . . . .43 2.2. Minimal PROPPATCH Response . . . . . . . . . . . . . . . 4 2.3. Minimal MKCALENDAR and MKCOL Responses . . . . . . . . .54 3. Reducing WebDAVRound-TripsRoundtrips with "return=representation" . . .. . . . . . . . . . . . . . . .5 3.1. Successful State-Changing Requests . . . . . . . . . . . 5 3.2. Unsuccessful Conditional State-Changing Requests . . . . . . . . . . . . . . . . . . . . . . . . 6 4. The "depth-noroot" Processing Preference . . . . . . . . . .76 5.Implementation Status .Security Considerations . . . . . . . . . . . . . . . . . . .76 6.SecurityIANA Considerations . . . . . . . . . . . . . . . . . . .9 7. IANA Considerations. . 7 6.1. Preference Registration . . . . . . . . . . . . . . . . . 7 6.2. Method References . .9 7.1. Preference Registration. . . . . . . . . . . . . . . . .9 7.2. Method. 7 6.3. Status Code References . . . . . . . . . . . . . . . . . 7 7. References . . . .10 7.3. Status Code References. . . . . . . . . . . . . . . . .10 8. Acknowledgements. . . . 8 7.1. Normative References . . . . . . . . . . . . . . . . . .10 9.8 7.2. Informative References . . . . . . . . . . . . . . . . . 9 Appendix A. The Brief and Extended Depth Header Fields . . . . . 10 Appendix B. Examples . . . .10 9.1. Normative References. . . . . . . . . . . . . . . . . . 109.2. Informative ReferencesB.1. PROPFIND . . . . . . . . . . . . . . . . .12 9.3. URIs. . . . . . .. . . . . . . . . . . . . . . . . . . 12 Appendix A. The Brief and Extended Depth Request Header Fields . 13 Appendix B. Examples . . . . . . . . . . . . . . . . . . . . . . 14 B.1. PROPFIND . . . . . . . . . . . . . . . . . . . . . . . . 1410 B.2. REPORT . . . . . . . . . . . . . . . . . . . . . . . . .1815 B.3. PROPPATCH . . . . . . . . . . . . . . . . . . . . . . . .2320 B.4. MKCOL . . . . . . . . . . . . . . . . . . . . . . . . . .2522 B.5. POST . . . . . . . . . . . . . . . . . . . . . . . . . .2623 B.6. PUT . . . . . . . . . . . . . . . . . . . . . . . . . . .30 Appendix C. Change Log27 Acknowledgements . . . . . . . . . . . . . . . . . . . . . .32. . 29 Author's Address . . . . . . . . . . . . . . . . . . . . . . . .3629 1. Introduction [RFC7240] defines theHTTPPreferrequestheader field and the "return=minimal"preferencepreference, whichindicatesindicate that a client wishes for the server to return a minimal response to a successfulrequest,request but states that what constitutes an appropriate minimal response is left solely to the discretion of the server. Section 2 of this specification defines precisely what is expected of a server when constructing minimal responses to successful WebDAV [RFC4918] requests. [RFC7240] also defines the "return=representation"preferencepreference, which indicates that a client wishes for the server to include an entity representing the current state of the resource in the response to a successful request. Section 3 of this specification makes recommendations on when this preference should be used by clients and extends its applicability to 412 (Precondition Failed) [RFC7232] responses. Finally, Section 4 of this specification defines the "depth-noroot" preference that can be used withWebDAVHTTP methods that support the"Depth"Depth header field. 1.1. Notational Conventions 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]. This document references XML element types in the "DAV:" [RFC4918], "urn:ietf:params:xml:ns:caldav" [RFC4791], and "urn:ietf:params:xml:ns:carddav" [RFC6352] namespaces outside of the context of an XML fragment. When doing so, the strings "DAV:", "CALDAV:", and "CARDDAV:" will be prepended to the XML elementtypestypes, respectively. 2. Reducing WebDAV Response Verbosity with "return=minimal" Some payload bodies in responses to WebDAV requests, such as 207 (Multi-Status) [RFC4918] responses, can be quite verbose or even unnecessary at times. This specification defines how the Preferrequestheader field, in conjunction with its "return=minimal" preference, can be used by clients to reduce the verbosity of such responses by requesting that the server omit those portions of the response that can be inferred by their absence. 2.1. Minimal PROPFIND and REPORT Responses When a PROPFIND [RFC4918] request, or a REPORT [RFC3253] request whose report type results in a 207 (Multi-Status) response, contains a Prefer header field with a preference of "return=minimal", the server SHOULD omit all DAV:propstat XML elements containing a DAV:status XML element of value 404 (Not Found) [RFC7231] from the 207 (Multi-Status) response. If the omission of such a DAV:propstat element would result in a DAV:response XML element containing zero DAV:propstat elements, the server MUST substitute one of the following in its place: o a DAV:propstat element consisting of an empty DAV:prop element and a DAV:status element of value 200 (OK) [RFC7231] o a DAV:status element of value 200 (OK) The following report types are candidates that could benefit from use of the "return=minimal" preference. NOTE: This list is not intended to be normative or exhaustive. o DAV:expand-property [RFC3253] o DAV:acl-principal-prop-set [RFC3744] o DAV:principal-property-search [RFC3744] o DAV:sync-collection [RFC6578] o CALDAV:calendar-query [RFC4791] o CALDAV:calendar-multiget [RFC4791] o CARDDAV:addressbook-query [RFC6352] o CARDDAV:addressbook-multiget [RFC6352] SeeAppendixAppendices B.1 andAppendixB.2 for examples. 2.2. Minimal PROPPATCH Response When a PROPPATCH [RFC4918] request contains a Prefer header field with a preference of "return=minimal", and all instructions are processed successfully, the server SHOULD return one of the following responses rather than a 207 (Multi-Status) response: o 204 (No Content) [RFC7231] o 200 (OK) [RFC7231] (preferably with a zero-length message body) See Appendix B.3 for examples. 2.3. Minimal MKCALENDAR and MKCOL Responses Both the MKCALENDAR [RFC4791] and Extended MKCOL [RFC5689] specifications indicate that a server MAY return a message body in response to a successful request. This specification explicitly defines the intended behavior in the presence of the Prefer header field. When a MKCALENDAR or anExtendedextended MKCOL request contains a Prefer header field with a preference of "return=minimal", and the collection is created with all requested properties being set successfully, the server SHOULD return a 201 (Created) [RFC7231] response with an empty (zero-length) message body. Note that the rationale for requiring that a minimal success response have an empty body is twofold: o[RFC4791][RFC4791], Section 5.3.1 states: "If a response body for a successful request is included, it MUST be a CALDAV:mkcalendar- response XML element." o[RFC5689][RFC5689], Section 3 states: "When an empty response body is returned with a success request status code, the client can assume that all properties were set." See Appendix B.4 for examples. 3. Reducing WebDAVRound-TripsRoundtrips with "return=representation" [RFC7240] describes the "return=representation" preference as being intended to provide a means of optimizing communication between the client and server by eliminating the need for a subsequent GET request to retrieve the current representation of the resource following a modification. This preference is equally applicable to situations where the server itself modifies a resource, and where a resource has been modified by another client. 3.1. Successful State-Changing Requests The state-changing methods PUT [RFC7231], COPY/MOVE [RFC4918], PATCH [RFC5789], and POST [RFC5995] can be used to create or update a resource. In some instances, such as withCalDAVCalendaring Extensions to WebDAV (CalDAV) Scheduling [RFC6638], the created or updated resource representation may differ from the representation sent in the body of the request or from that referenced by the effective request URI. In cases where the client, upon receiving a 2xx (Successful) [RFC7231] response to its state-changing request, would normally issue a subsequent GET request to retrieve the current representation of the resource, the client can instead include a Prefer header field with the "return=representation" preference in the state-changing request. When a state-changing request contains a Prefer header field with a preference of "return=representation", and the resource is created or updated successfully, the server SHOULD include an entity representing the current state of the resource in the resulting 201 (Created) or 200 (OK) [RFC7231] response. In addition to coalescing the create/update and retrieve operations into a singleround-trip,roundtrip, by returning the current representation of the resource in theresponseresponse, the client will know that any changes to the resource were produced by the server rather than a concurrent client, thus providing a level of atomicity to the operation. See Appendix B.5 for examples. 3.2. Unsuccessful Conditional State-Changing Requests Frequently, clients using a state-changing method such as those listed above will make them conditional by including either anIf- MatchIf-Match or an If-None-Match [RFC7232] header field in the request. This is done to prevent the client from accidentally overwriting a resource whose current state has been modified by another client acting in parallel. In cases where the client, upon receiving a 412 (Precondition Failed) [RFC7232] response to its conditional state- changing request, would normally issue a subsequent GET request to retrieve the current representation of the resource, the client can instead include a Prefer header field with the "return=representation" preference in the conditional state-changing request. When a conditional state-changing request contains a Prefer header field with a preference of "return=representation", and the specified condition evaluates to false, the server SHOULD include an entity representing the current state of the resource in the resulting 412 (Precondition Failed) [RFC7232] response. See Appendix B.6 for examples. 4. The "depth-noroot" Processing Preference The "depth-noroot" preference indicates that the client wishes for the server to exclude the target (root) resource from processing by theWebDAVHTTP method and only apply theWebDAVHTTP method to the target resource's subordinate resources. This preference is only intended to be used withWebDAVHTTP methods whose definitions explicitly provide support for the Depth [RFC4918] header field. Furthermore, this preference only applies when the Depth header field has a value of "1" or "infinity" (either implicitly or explicitly). The "depth-noroot" preference MAY be used in conjunction with the "return=minimal" preference in a single request. See Appendix B.1 for examples. 5.Implementation Status < RFC Editor: before publication please remove this section, the reference to [RFC7942], and section 9.3 ("URIs")> This section records the status of known implementations of the protocol definedSecurity Considerations No new security considerations are introduced bythis specification at the time of postinguse ofthis Internet-Draft,the Prefer header field with WebDAV requests, beyond those discussed in [RFC7240] andis based on a proposal describedthose already inherent in[RFC7942].those requests. 6. IANA Considerations 6.1. Preference Registration Thedescription of implementations in this section is intendedfollowing preference has been added toassisttheIETF in its decision processesHTTP Preferences Registry defined inprogressing drafts to RFCs. Please noteSection 5.1 of [RFC7240]. Preference: depth-noroot Description: The "depth-noroot" preference indicates that thelisting of any individual implementation here does not imply endorsement byclient wishes for theIETF. Furthermore, no effort has been spentserver toverifyexclude theinformation presented here that was suppliedtarget (root) resource from processing byIETF contributors. This is not intended as,the HTTP method andmust not be construed to be, a catalog of available implementations or their features. Readers are advised to note that other implementations may exist. According to [RFC7942], "this will allow reviewers and working groups to assign due consideration to documents that have the benefit of running code, which may serve as evidence of valuable experimentation and feedback that have made the implemented protocols more mature. It is up to the individual working groups to use this information as they see fit". 5.1. Cyrus The open source Cyrus [4] project is a highly scalable enterprise mail system which also supports calendaring and contacts. This production level CalDAV/CardDAV implementation supports all of the preferences described in this document and successfully interoperates with the CalDAVTester, Apple Calendar and Apple Contacts, and aCal client implementations described below. This implementation is freely distributable under a BSD style license from Computing Services at Carnegie Mellon University [5]. 5.2. Calendar and Contacts Server The open source Calendar and Contacts Server [6] project is a standards-compliant server implementing the CalDAV and CardDAV protocols. This production level implementation supports all of the preferences described in this document and successfully interoperates with the CalDAVTester and Apple Calendar and Apple Contacts client implementations described below. This implementation is freely distributable under the terms of the Apache License, Version 2.0 [7]. 5.3. Bedework Bedework [8] is an open-source enterprise calendar system that supports public, personal, and group calendaring. This production level implementation supports the "return=minimal" preference described in this document and successfully interoperates with the CalDAVTester client implementation described below. This implementation is freely distributable under the Jasig Licensing Policy [9]. 5.4. DAViCal DAViCal [10] is a server for calendar sharing using the CalDAV protocol. This production level implementation supports the "return=minimal" preference described in this document and successfully interoperates with the CalDAVTester client implementation described below. This implementation is Free Software [11] distributable under the General Public License [12]. 5.5. Apple Calendar and Apple Contacts The widely used Apple Calendar and Apple Contacts [13] clients are standards-compliant clients implementing the CalDAV and CardDAV protocols respectively. These production level implementations support the "return=minimal" preference described in this document and successfully interoperate with the Cyrus and Calendar and Contacts Server implementations described above. These client implementations are proprietary and are distributed as part of Apple's desktop operating systems. 5.6. aCal aCal [14] is an open source calendar client for Android which uses the CalDAV standard for communication. This implementation makes some use of each of the preferences described in this document and successfully interoperates with the Cyrus server implementation described above. This implementation is freely distributable under the General Public License [15]. 5.7. CalDAVTester CalDAVTester [16] is an open source test and performance application designed to work with CalDAV and/or CardDAV servers and tests various aspects of their protocol handling as well as performance. This widely used implementation supports all of the preferences described in this document and successfully interoperates with the server implementations described above. This implementation is freely distributable under the terms of the Apache License, Version 2.0 [17]. 6. Security Considerations No new security considerations are introduced by use of the Prefer header field with WebDAV request methods, beyond those discussed in [RFC7240] and those already inherent in those methods. 7. IANA Considerations 7.1. Preference Registration The following preference is to be added to the HTTP Preferences Registry defined in Section 5.1 of [RFC7240]. Preference: depth-noroot Description: The "depth-noroot" preference indicates that the client wishes for the server to exclude the target (root) resource from processing by the WebDAV method and only apply the WebDAV methodonly apply the HTTP method to the target resource's subordinate resources. Reference:RFCXXXX,RFC 8144, Section 4 Notes: This preference is only intended to be used withWebDAVHTTP methods whose definitions explicitly provide support for the"Depth"Depth [RFC4918] header field. Furthermore, this preference only applies when the"Depth"Depth header field has a value of "1" or "infinity" (either implicitly or explicitly).7.2.6.2. Method References The following methodsare tohave had their references updated in theHTTP"HTTP MethodRegistry (<http://www.iana.org/assignments/http- methods>). +------------+------------------------------------------------------+Registry" (http://www.iana.org/assignments/http-methods). +------------+------+------------+----------------------------------+ | Method | Safe | Idempotent | References | | Name | |+------------+------------------------------------------------------+| | +------------+------+------------+----------------------------------+ | MKCALENDAR |RFC4791,no | yes | RFC 4791, Section 5.3.1;RFCXXXX,RFC | | | | | 8144, Section 2.3 | | MKCOL |RFC4918,no | yes | RFC 4918, Section 9.3; RFC 5689,Section 3; RFCXXXX,| | | | | Section 3; RFC 8144, Section 2.3 | | PROPFIND |RFC4918,yes | yes | RFC 4918, Section 9.1;RFCXXXX,RFC 8144, | | | | | Section 2.1 | | PROPPATCH |RFC4918,no | yes | RFC 4918, Section 9.2;RFCXXXX,RFC 8144, | | | | | Section 2.2 | | REPORT |RFC3253,yes | yes | RFC 3253, Section 3.6;RFCXXXX, Section 2.1 | +------------+------------------------------------------------------+ 7.3. Status Code References The following status code is to have its references updated in the HTTP Status Code Registry (<http://www.iana.org/assignments/http- status-codes>). +-------+--------------------------------------------+RFC 8144, |Value|References|+-------+--------------------------------------------+|412|RFC7232, Section 4.2; RFCXXXX,Section3.22.1 |+-------+--------------------------------------------+ 8. Acknowledgements The author would like to thank the following individuals for contributing their ideas and support for writing this specification: Cyrus Daboo, Helge Hess, Andrew McMillan, Arnaud Quillaud, and Julian Reschke. The author would also like to thank+------------+------+------------+----------------------------------+ 6.3. Status Code References The following status code has had its references updated in theCalendaring and Scheduling Consortium for advice with this specification, and for organizing interoperability testing events to help refine it. 9."HTTP Status Codes" registry (http://www.iana.org/assignments/http-status- codes). +-------+-------------------+---------------------------------------+ | Value | Description | References | +-------+-------------------+---------------------------------------+ | 412 | Precondition | RFC 7232, Section 4.2; RFC 8144, | | | Failed | Section 3.2 | +-------+-------------------+---------------------------------------+ 7. References9.1.7.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, <http://www.rfc-editor.org/info/rfc2119>. [RFC3253] Clemm, G., Amsden, J., Ellison, T., Kaler, C., and J. Whitehead, "Versioning Extensions to WebDAV (Web Distributed Authoring and Versioning)", RFC 3253, DOI 10.17487/RFC3253, March 2002, <http://www.rfc-editor.org/info/rfc3253>. [RFC4791] Daboo, C., Desruisseaux, B., and L. Dusseault, "Calendaring Extensions to WebDAV (CalDAV)", RFC 4791, DOI 10.17487/RFC4791, March 2007, <http://www.rfc-editor.org/info/rfc4791>. [RFC4918] Dusseault, L., Ed., "HTTP Extensions for Web Distributed Authoring and Versioning (WebDAV)", RFC 4918, DOI 10.17487/RFC4918, June 2007, <http://www.rfc-editor.org/info/rfc4918>. [RFC5689] Daboo, C., "Extended MKCOL for Web Distributed Authoring and Versioning (WebDAV)", RFC 5689, DOI 10.17487/RFC5689, September 2009, <http://www.rfc-editor.org/info/rfc5689>. [RFC5789] Dusseault, L. and J. Snell, "PATCH Method for HTTP", RFC 5789, DOI 10.17487/RFC5789, March 2010, <http://www.rfc-editor.org/info/rfc5789>. [RFC5995] Reschke, J., "Using POST to Add Members to Web Distributed Authoring and Versioning (WebDAV) Collections", RFC 5995, DOI 10.17487/RFC5995, September 2010, <http://www.rfc-editor.org/info/rfc5995>. [RFC7231] Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer Protocol (HTTP/1.1): Semantics and Content", RFC 7231, DOI 10.17487/RFC7231, June 2014, <http://www.rfc-editor.org/info/rfc7231>. [RFC7232] Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer Protocol (HTTP/1.1): Conditional Requests", RFC 7232, DOI 10.17487/RFC7232, June 2014, <http://www.rfc-editor.org/info/rfc7232>. [RFC7240] Snell, J., "Prefer Header for HTTP", RFC 7240, DOI 10.17487/RFC7240, June 2014, <http://www.rfc-editor.org/info/rfc7240>.9.2.7.2. Informative References [MSDN.aa493854] Microsoft Developer Network, "PROPPATCH Method", June 2006, <http://msdn.microsoft.com/en-us/library/aa493854.aspx>. [MSDN.aa563501] Microsoft Developer Network, "Brief Header", June 2006, <http://msdn.microsoft.com/en-us/library/aa563501.aspx>. [MSDN.aa563950] Microsoft Developer Network, "Depth Header", June 2006, <http://msdn.microsoft.com/en-us/library/aa563950.aspx>. [MSDN.aa580336] Microsoft Developer Network, "PROPFIND Method", June 2006, <http://msdn.microsoft.com/en-us/library/aa580336.aspx>. [RFC3744] Clemm, G., Reschke, J., Sedlar, E., and J. Whitehead, "Web Distributed Authoring and Versioning (WebDAV) Access Control Protocol", RFC 3744, DOI 10.17487/RFC3744, May 2004, <http://www.rfc-editor.org/info/rfc3744>. [RFC6352] Daboo, C., "CardDAV: vCard Extensions to Web Distributed Authoring and Versioning (WebDAV)", RFC 6352, DOI 10.17487/RFC6352, August 2011, <http://www.rfc-editor.org/info/rfc6352>. [RFC6578] Daboo, C. and A. Quillaud, "Collection Synchronization for Web Distributed Authoring and Versioning (WebDAV)", RFC 6578, DOI 10.17487/RFC6578, March 2012, <http://www.rfc-editor.org/info/rfc6578>. [RFC6638] Daboo, C. and B. Desruisseaux, "Scheduling Extensions to CalDAV", RFC 6638, DOI 10.17487/RFC6638, June 2012, <http://www.rfc-editor.org/info/rfc6638>.[RFC7942] Sheffer, Y. and A. Farrel, "Improving Awareness of Running Code: The Implementation Status Section", BCP 205, RFC 7942, DOI 10.17487/RFC7942, July 2016, <http://www.rfc-editor.org/info/rfc7942>. 9.3. URIs [1] http://www.cyrusimap.org/ [2] http://www.cmu.edu/computing/ [3] http://calendarserver.org/ [4] http://www.apache.org/licenses/LICENSE-2.0.html [5] http://www.bedework.org/ [6] http://www.jasig.org/licensing [7] http://www.davical.org/ [8] http://www.gnu.org/philosophy/open-source-misses-the-point.html [9] http://www.gnu.org/licenses/gpl.html [10] http://www.apple.com/macos/ [11] http://www.acal.me/ [12] http://www.gnu.org/licenses/gpl.html [13] http://calendarserver.org/wiki/CalDAVTester [14] http://www.apache.org/licenses/LICENSE-2.0.htmlAppendix A. The Brief and Extended DepthRequestHeader Fields This document is based heavily on the Brief [MSDN.aa563501] and extended Depth [MSDN.aa563950]requestheader fields. The behaviors described inSectionSections 2.1 andSection2.2 are identical to those provided by the Brief header field when used with the PROPFIND [MSDN.aa580336] and PROPPATCH [MSDN.aa493854]methodsmethods, respectively. The behavior described in Section 4 is identical to that provided by the "1,noroot" [MSDN.aa563950] and "infinity,noroot" [MSDN.aa563950] Depth header field values. Client and server implementations that already support the Brief header field can add support for the "return=minimal" preference with nominal effort. If a server supporting the Prefer header field receives both the Brief and Prefer header fields in a request, clients can expect the server to ignore the Brief header field and only use the Prefer header field preferences. Appendix B. Examples B.1. PROPFIND B.1.1. Typical PROPFINDrequest/responseRequest/Response with Depth:1 This example tries to fetch one known and one unknown property from child resources. >> Request << PROPFIND /container/ HTTP/1.1 Host: webdav.example.com Content-Type: application/xml; charset=utf-8 Content-Length:xxxx189 Depth: 1 <?xml version="1.0" encoding="UTF-8"?> <D:propfind xmlns:D="DAV:" xmlns:X="http://ns.example.com/foobar/"> <D:prop> <D:resourcetype/> <X:foobar/> </D:prop> </D:propfind> >> Response << HTTP/1.1 207 Multi-Status Content-Type: application/xml; charset=utf-8 Content-Length:xxxx1722 <?xml version="1.0" encoding="utf-8"?> <D:multistatus xmlns:D="DAV:" xmlns:X="http://ns.example.com/foobar/"> <D:response> <D:href>/container/</D:href> <D:propstat> <D:prop> <D:resourcetype> <D:collection/> </D:resourcetype> </D:prop> <D:status>HTTP/1.1 200 OK</D:status> </D:propstat> <D:propstat> <D:prop> <X:foobar/> </D:prop> <D:status>HTTP/1.1 404 Not Found</D:status> </D:propstat> </D:response> <D:response> <D:href>/container/work/</D:href> <D:propstat> <D:prop> <D:resourcetype> <D:collection/> </D:resourcetype> </D:prop> <D:status>HTTP/1.1 200 OK</D:status> </D:propstat> <D:propstat> <D:prop> <X:foobar/> </D:prop> <D:status>HTTP/1.1 404 Not Found</D:status> </D:propstat> </D:response> <D:response> <D:href>/container/home/</D:href> <D:propstat> <D:prop> <D:resourcetype> <D:collection/> </D:resourcetype> </D:prop> <D:status>HTTP/1.1 200 OK</D:status> </D:propstat> <D:propstat> <D:prop> <X:foobar/> </D:prop> <D:status>HTTP/1.1 404 Not Found</D:status> </D:propstat> </D:response> <D:response> <D:href>/container/foo.txt</D:href> <D:propstat> <D:prop> <D:resourcetype/> </D:prop> <D:status>HTTP/1.1 200 OK</D:status> </D:propstat> <D:propstat> <D:prop> <X:foobar/> </D:prop> <D:status>HTTP/1.1 404 Not Found</D:status> </D:propstat> </D:response> </D:multistatus> B.1.2. Minimal PROPFINDrequest/responseRequest/Response with Depth:1 This example tries to fetch one known and one unknown property from child resources only. >> Request << PROPFIND /container/ HTTP/1.1 Host: webdav.example.com Content-Type: application/xml; charset=utf-8 Content-Length:xxxx189 Depth: 1 Prefer: return=minimal, depth-noroot <?xml version="1.0" encoding="UTF-8"?> <D:propfind xmlns:D="DAV:" xmlns:X="http://ns.example.com/foobar/"> <D:prop> <D:resourcetype/> <X:foobar/> </D:prop> </D:propfind> >> Response << HTTP/1.1 207 Multi-Status Content-Type: application/xml; charset=utf-8 Content-Length:xxxx837 Preference-Applied: return=minimal, depth-noroot <?xml version="1.0" encoding="utf-8"?> <D:multistatus xmlns:D="DAV:"> <D:response> <D:href>/container/work/</D:href> <D:propstat> <D:prop> <D:resourcetype> <D:collection/> </D:resourcetype> </D:prop> <D:status>HTTP/1.1 200 OK</D:status> </D:propstat> </D:response> <D:response> <D:href>/container/home/</D:href> <D:propstat> <D:prop> <D:resourcetype> <D:collection/> </D:resourcetype> </D:prop> <D:status>HTTP/1.1 200 OK</D:status> </D:propstat> </D:response> <D:response> <D:href>/container/foo.txt</D:href> <D:propstat> <D:prop> <D:resourcetype/> </D:prop> <D:status>HTTP/1.1 200 OK</D:status> </D:propstat> </D:response> </D:multistatus> B.1.3. Minimal PROPFINDrequest/responseRequest/Response with anemptyEmpty DAV:propstatelementElement This example tries to fetch an unknown property from a collection. >> Request << PROPFIND /container/ HTTP/1.1 Host: webdav.example.com Content-Type: application/xml; charset=utf-8 Content-Length:xxxx166 Prefer: return=minimal <?xml version="1.0" encoding="UTF-8"?> <D:propfind xmlns:D="DAV:" xmlns:X="http://ns.example.com/foobar/"> <D:prop> <X:foobar/> </D:prop> </D:propfind> >> Response << HTTP/1.1 207 Multi-Status Content-Type: application/xml; charset=utf-8 Content-Length:xxxx255 Preference-Applied: return=minimal <?xml version="1.0" encoding="utf-8"?> <D:multistatus xmlns:D="DAV:"> <D:response> <D:href>/container/</D:href> <D:propstat> <D:prop/> <D:status>HTTP/1.1 200 OK</D:status> </D:propstat> </D:response> </D:multistatus> B.2. REPORT B.2.1. Typical REPORTrequest/responseRequest/Response This example tries to fetch an unknown property from several resources via the DAV:expand-property [RFC3253] REPORT type. >> Request << REPORT /dav/principals/ HTTP/1.1 Host: webdav.example.com Content-type: text/xml; charset=utf-8 Content-length:xxxx847 <?xml version="1.0" encoding="utf-8"?> <D:expand-property xmlns:D="DAV:"> <D:property name="current-user-principal"> <D:property name="resourcetype"/> <D:property name="displayname"/> <D:property name="foobar" namespace="http://ns.example.com/foobar"/> <D:property name="calendar-home-set" namespace="urn:ietf:params:xml:ns:caldav"> <D:property name="resourcetype"/> <D:property name="foobar" namespace="http://ns.example.com/foobar"/> </D:property> <D:property name="addressbook-home-set" namespace="urn:ietf:params:xml:ns:carddav"> <D:property name="resourcetype"/> <D:property name="foobar" namespace="http://ns.example.com/foobar"/> </D:property> </D:property> </D:expand-property> >> Response << HTTP/1.1 207 Multi-Status Content-Type: application/xml; charset=utf-8 Content-Length:xxxx2664 <?xml version="1.0" encoding="utf-8"?> <D:multistatus xmlns:D="DAV:" xmlns:C="urn:ietf:params:xml:ns:caldav" xmlns:R="urn:ietf:params:xml:ns:carddav" xmlns:X="http://ns.example.com/foobar"> <D:response> <D:href>/dav/principals/</D:href> <D:propstat> <D:prop> <D:current-user-principal> <D:response> <D:href>/dav/principals/user/ken/</D:href> <D:propstat> <D:prop> <D:resourcetype> <D:principal/> </D:resourcetype> <D:displayname>ken</D:displayname> <C:calendar-home-set> <D:response> <D:href>/dav/calendars/user/ken/</D:href> <D:propstat> <D:prop> <D:resourcetype> <D:collection/> </D:resourcetype> </D:prop> <D:status>HTTP/1.1 200 OK</D:status> </D:propstat> <D:propstat> <D:prop> <X:foobar/> </D:prop> <D:status>HTTP/1.1 404 Not Found</D:status> </D:propstat> </D:response> </C:calendar-home-set> <R:addressbook-home-set> <D:response> <D:href>/dav/addressbooks/user/ken/</D:href> <D:propstat> <D:prop> <D:resourcetype> <D:collection/> </D:resourcetype> </D:prop> <D:status>HTTP/1.1 200 OK</D:status> </D:propstat> <D:propstat> <D:prop> <X:foobar/> </D:prop> <D:status>HTTP/1.1 404 Not Found</D:status> </D:propstat> </D:response> </R:addressbook-home-set> </D:prop> <D:status>HTTP/1.1 200 OK</D:status> </D:propstat> <D:propstat> <D:prop> <X:foobar/> </D:prop> <D:status>HTTP/1.1 404 Not Found</D:status> </D:propstat> </D:response> </D:current-user-principal> </D:prop> <D:status>HTTP/1.1 200 OK</D:status> </D:propstat> </D:response> </D:multistatus> B.2.2. Minimal REPORTrequest/responseRequest/Response This example tries to fetch an unknown property from several resources via the DAV:expand-property [RFC3253] REPORT type. >> Request << REPORT /dav/principals/ HTTP/1.1 Host: webdav.example.com Content-Type: application/xml; charset=utf-8 Content-Length:xxxx847 Prefer: return=minimal <?xml version="1.0" encoding="utf-8"?> <D:expand-property xmlns:D="DAV:"> <D:property name="current-user-principal"> <D:property name="resourcetype"/> <D:property name="displayname"/> <D:property name="foobar" namespace="http://ns.example.com/foobar"/> <D:property name="calendar-home-set" namespace="urn:ietf:params:xml:ns:caldav"> <D:property name="resourcetype"/> <D:property name="foobar" namespace="http://ns.example.com/foobar"/> </D:property> <D:property name="addressbook-home-set" namespace="urn:ietf:params:xml:ns:carddav"> <D:property name="resourcetype"/> <D:property name="foobar" namespace="http://ns.example.com/foobar"/> </D:property> </D:property> </D:expand-property> >> Response << HTTP/1.1 207 Multi-Status Content-Type: application/xml; charset=utf-8 Content-Length:xxxx1998 Preference-Applied: return=minimal <?xml version="1.0" encoding="utf-8"?> <D:multistatus xmlns:D="DAV:" xmlns:C="urn:ietf:params:xml:ns:caldav" xmlns:R="urn:ietf:params:xml:ns:carddav" xmlns:X="http://ns.example.com/foobar"> <D:response> <D:href>/dav/principals/</D:href> <D:propstat> <D:prop> <D:current-user-principal> <D:response> <D:href>/dav/principals/user/ken/</D:href> <D:propstat> <D:prop> <D:resourcetype> <D:principal/> </D:resourcetype> <D:displayname>ken</D:displayname> <C:calendar-home-set> <D:response> <D:href>/dav/calendars/user/ken/</D:href> <D:propstat> <D:prop> <D:resourcetype> <D:collection/> </D:resourcetype> </D:prop> <D:status>HTTP/1.1 200 OK</D:status> </D:propstat> </D:response> </C:calendar-home-set> <R:addressbook-home-set> <D:response> <D:href>/dav/addressbooks/user/ken/</D:href> <D:propstat> <D:prop> <D:resourcetype> <D:collection/> </D:resourcetype> </D:prop> <D:status>HTTP/1.1 200 OK</D:status> </D:propstat> </D:response> </R:addressbook-home-set> </D:prop> <D:status>HTTP/1.1 200 OK</D:status> </D:propstat> </D:response> </D:current-user-principal> </D:prop> <D:status>HTTP/1.1 200 OK</D:status> </D:propstat> </D:response> </D:multistatus> B.3. PROPPATCH B.3.1. Typical PROPPATCHrequest/responseRequest/Response >> Request << PROPPATCH /container/ HTTP/1.1 Host: webdav.example.com Content-Type: application/xml; charset=utf-8 Content-Length:xxxx199 <?xml version="1.0" encoding="utf-8"?> <D:propertyupdate xmlns:D="DAV:"> <D:set> <D:prop> <D:displayname>My Container</D:displayname> </D:prop> </D:set> </D:propertyupdate> >> Response << HTTP/1.1 207 Multi-Status Content-Type: application/xml; charset=utf-8 Content-Length:xxxx297 <?xml version="1.0" encoding="utf-8"?> <D:multistatus xmlns:D="DAV:"> <D:response> <D:href>/container/</D:href> <D:propstat> <D:prop> <D:displayname/> </D:prop> <D:status>HTTP/1.1 200 OK</D:status> </D:propstat> </D:response> </D:multistatus> B.3.2. Minimal PROPPATCHrequest/responseRequest/Response >> Request << PROPPATCH /container/ HTTP/1.1 Host: webdav.example.com Content-Type: application/xml; charset=utf-8 Content-Length:xxxx199 Prefer: return=minimal <?xml version="1.0" encoding="utf-8"?> <D:propertyupdate xmlns:D="DAV:"> <D:set> <D:prop> <D:displayname>My Container</D:displayname> </D:prop> </D:set> </D:propertyupdate> >> Response << HTTP/1.1 200 OK Content-Length: 0 Preference-Applied: return=minimal B.4. MKCOL B.4.1. Verbose MKCOLrequest/responseRequest/Response >> Request << MKCOL /container/ HTTP/1.1 Host: webdav.example.com Content-Type: application/xml; charset=utf-8 Content-Length:xxxx181 <?xml version="1.0" encoding="utf-8"?> <D:mkcol xmlns:D="DAV:"> <D:set> <D:prop> <D:displayname>My Container</D:displayname> </D:prop> </D:set> </D:mkcol> >> Response << HTTP/1.1 201 Created Cache-Control: no-cache Content-Type: application/xml; charset=utf-8 Content-Length:xxxx224 <?xml version="1.0" encoding="utf-8"?> <D:mkcol-response xmlns:D="DAV:"> <D:propstat> <D:prop> <D:displayname/> </D:prop> <D:status>HTTP/1.1 200 OK</D:status> </D:propstat> </D:mkcol-response> B.4.2. Minimal MKCOLrequest/responseRequest/Response >> Request << MKCOL /container/ HTTP/1.1 Host: webdav.example.com Content-Type: application/xml; charset=utf-8 Content-Length:xxxx181 Prefer: return=minimal <?xml version="1.0" encoding="utf-8"?> <D:mkcol xmlns:D="DAV:"> <D:set> <D:prop> <D:displayname>My Container</D:displayname> </D:prop> </D:set> </D:mkcol> >> Response << HTTP/1.1 201 Created Cache-Control: no-cache Content-Length: 0 Preference-Applied: return=minimal B.5. POST B.5.1. Typicalresource creationResource Creation andretrievalRetrieval via POST + GET Note that this request is not conditional because by using the POST [RFC5995]methodmethod, the client lets the server choose the resource URI, thereby guaranteeing that it will not modify an existing resource. >> Request << POST /container/work;add-member/ HTTP/1.1 Host: caldav.example.com Content-Type: text/calendar; charset=utf-8 Content-Length:xxxx521 BEGIN:VCALENDAR VERSION:2.0 PRODID:-//Example Corp.//CalDAV Client//EN BEGIN:VEVENT UID:CD87465FA SEQUENCE:0 DTSTAMP:20120602T185254Z DTSTART:20120602T160000Z DTEND:20120602T170000Z TRANSP:OPAQUE SUMMARY:Lunch ORGANIZER;CN="Ken Murchison":mailto:murch@example.com ATTENDEE;CN="Ken Murchison";CUTYPE=INDIVIDUAL;PARTSTAT=ACCEPTED: mailto:murch@example.com ATTENDEE;CN="John Doe";CUTYPE=INDIVIDUAL;PARTSTAT =NEEDS-ACTION;ROLE=REQ-PARTICIPANT;RSVP=TRUE:mailto:jdoe@ example.com END:VEVENT END:VCALENDAR >> Response << HTTP/1.1 201 Created Location: /container/work/abc.ics Content-Length: 0 Note that the server did not include any validator header fields(e.g(e.g., ETag) in the response, signaling that the created representation differs from the representation sent in the body of the request. The client has to send a separate GET request to retrieve the current representation: >> Request << GET /container/work/abc.ics HTTP/1.1 Host: caldav.example.com >> Response << HTTP/1.1 200 OK Content-Type: text/calendar; charset=utf-8 Content-Length:xxxx541 ETag: "nahduyejc" Schedule-Tag: "jfd84hgbcn" BEGIN:VCALENDAR VERSION:2.0 PRODID:-//Example Corp.//CalDAV Server//EN BEGIN:VEVENT UID:CD87465FA SEQUENCE:0 DTSTAMP:20120602T185300Z DTSTART:20120602T160000Z DTEND:20120602T170000Z TRANSP:OPAQUE SUMMARY:Lunch ORGANIZER;CN="Ken Murchison":mailto:murch@example.com ATTENDEE;CN="Ken Murchison";CUTYPE=INDIVIDUAL;PARTSTAT=ACCEPTED: mailto:murch@example.com ATTENDEE;CN="John Doe";CUTYPE=INDIVIDUAL;PARTSTAT =NEEDS-ACTION;ROLE=REQ-PARTICIPANT;RSVP=TRUE;SCHEDULE-STATUS= 1.2:mailto:jdoe@example.com END:VEVENT END:VCALENDAR B.5.2. Streamlinedresource creationResource Creation andretrievalRetrieval via POST Note that this request is not conditional because by using the POST [RFC5995]methodmethod, the client lets the server choose the resource URI, thereby guaranteeing that it will not modify an existing resource. >> Request << POST /container/work;add-member/ HTTP/1.1 Host: caldav.example.com Content-Type: text/calendar; charset=utf-8 Content-Length:xxxx521 Prefer: return=representation BEGIN:VCALENDAR VERSION:2.0 PRODID:-//Example Corp.//CalDAV Client//EN BEGIN:VEVENT UID:CD87465FA SEQUENCE:0 DTSTAMP:20120602T185254Z DTSTART:20120602T160000Z DTEND:20120602T170000Z TRANSP:OPAQUE SUMMARY:Lunch ORGANIZER;CN="Ken Murchison":mailto:murch@example.com ATTENDEE;CN="Ken Murchison";CUTYPE=INDIVIDUAL;PARTSTAT=ACCEPTED: mailto:murch@example.com ATTENDEE;CN="John Doe";CUTYPE=INDIVIDUAL;PARTSTAT =NEEDS-ACTION;ROLE=REQ-PARTICIPANT;RSVP=TRUE:mailto:jdoe@ example.com END:VEVENT END:VCALENDAR >> Response << HTTP/1.1 201 Created Location: /container/work/abc.ics Content-Type: text/calendar; charset=utf-8 Content-Length:xxxx541 Content-Location: /container/work/abc.ics ETag: "nahduyejc" Schedule-Tag: "jfd84hgbcn" Preference-Applied: return=representation BEGIN:VCALENDAR VERSION:2.0 PRODID:-//Example Corp.//CalDAV Server//EN BEGIN:VEVENT UID:CD87465FA SEQUENCE:0 DTSTAMP:20120602T185300Z DTSTART:20120602T160000Z DTEND:20120602T170000Z TRANSP:OPAQUE SUMMARY:Lunch ORGANIZER;CN="Ken Murchison":mailto:murch@example.com ATTENDEE;CN="Ken Murchison";CUTYPE=INDIVIDUAL;PARTSTAT=ACCEPTED: mailto:murch@example.com ATTENDEE;CN="John Doe";CUTYPE=INDIVIDUAL;PARTSTAT =NEEDS-ACTION;ROLE=REQ-PARTICIPANT;RSVP=TRUE;SCHEDULE-STATUS= 1.2:mailto:jdoe@example.com END:VEVENT END:VCALENDAR B.6. PUT B.6.1. Typicalconditional resource update failureConditional Resource Update Failure andretrievalRetrieval via PUT + GET >> Request << PUT /container/motd.txt HTTP/1.1 Host: dav.example.com Content-Type: text/plain Content-Length:xxxx69 If-Match: "asd973" Either write something worth reading or do something worth writing. >> Response << HTTP/1.1 412 Precondition Failed Content-Length: 0 The resource has been modified by another user agent (ETagmismatch), thereforemismatch); therefore, the client has to send a separate GET request to retrieve the current representation: >> Request << GET /container/motd.txt HTTP/1.1 Host: dav.example.com >> Response << HTTP/1.1 200 OK Content-Type: text/plain Content-Length:xxxx52 ETag: "789sdas" An investment in knowledge pays the best interest. B.6.2. Streamlinedconditional resource update failureConditional Resource Update Failure andretrievalRetrieval via PUT >> Request << PUT /container/motd.txt HTTP/1.1 Host: dav.example.com Content-Type: text/plain Content-Length:xxxx69 If-Match: "asd973" Prefer: return=representation Either write something worth reading or do something worth writing. >>Response << HTTP/1.1 412 Precondition Failed Content-Type: text/plain Content-Length: xxxx Content-Location: /container/motd.txt ETag: "789sdas" Preference-Applied: return=representation An investment in knowledge pays the best interest. Appendix C. Change Log < RFC Editor: before publication please remove this section > C.1. Since -13 o More editorial and formatting changes from Julian Reschke. o Re-introduced RFC 7240 to Abstract per Gen-ART review. C.2. Since -12 o Several editorial and formatting changes from Julian Reschke. C.3. Since -11 o Several fixes per Gen-ART Review (Stuart Bryant): * Added "updates RFC7240" text to Abstract. * Removed "Open Issues" Section. * Added RFC Editor note to remove "URIs" Section. * Fixed typos. C.4. Since -10 o Pared down Updates per Alexey. o Added self-reference for 412 status code in registry. C.5. Since -09 o Combined PROPFIND and REPORT sections o Added several more RFCs to Updated list. o Added list of report types that can benefit from "return=minimal". o Changed REPORT example to use DAV:expand-property. o Added IANA section to update HTTP Method Registry references. o Split "return=representation" discussion into two separate sections and expanded text. o Updated Open Issues with new questions. o Several editorial changes from Julian Reschke. C.6. Since -08 o Moved examples to Appendix B. o Added reference to HTTP PATCH. o Updated Implementation Status reference from RFC 6982 to RFC 7942. C.7. Since -07 o No substantive changes. Refreshed due to pending expiration. C.8. Since -06 o Updated HTTPbis and Prefer references to published RFCs. C.9. Since -05 o Allow a minimal PROPFIND/REPORT response to contain a DAV:status element rather than an empty DAV:propstat element. o Allow 204 (No Content) as a minimal PROPATCH success response. o Added justification for why a minimal MKCOL/MKCALENDAR success response must have an empty body. o Added text and an example of how "return=representation" can be employed with a conditional state-changing request and aResponse << HTTP/1.1 412(Precondition Failed) response. o Added a note to the POST+GET example bringing attention to the lack of a validator header fieldPrecondition Failed Content-Type: text/plain Content-Length: 52 Content-Location: /container/motd.txt ETag: "789sdas" Preference-Applied: return=representation An investment in knowledge pays thePOST response. o Reduced the number of inline references. o Limited most examplesbest interest. Acknowledgements The author would like tovanilla WebDAV. o Reduced number of items in TOC. o Removed the recommendation thatthank thelegacy Brief header functionality should be implemented. o Added note about how a server should handle a request that contains both Brieffollowing individuals for contributing their ideas andPrefer. o Other editorial tweaks from Julian Reschke. C.10. Since -04 o Added note stating where to send comments. C.11. Since -03 o Limited "Updates" to just RFC 4918. o Consensus from CalConnect membership that a "depth-root" option is unnecessary atsupport for writing thispoint. o Consensus from CalConnect membership to remove Vary header field from PROPFINDspecification: Cyrus Daboo, Helge Hess, Andrew McMillan, Arnaud Quillaud, andREPORT responses since these responses don't appear to be cached. o Updated "Implementation Status" section boilerplate to RFC 6982. o Added aCal to "Implementation Status" section. o Added note that servers SHOULD respond with Preference-Applied when return=minimal is used with PROPFIND or REPORT. C.12. Since -02 o Reintroduced "Updates" to header. o Added text noting that "return=representation" provides a level of atomicityJulian Reschke. The author would also like to thank theoperation. o Added "Implementation Status" section. o Tweaked/corrected some examples.. o Updated HTTPbis references. C.13. Since -01 o Removed "Updates" from header. o Fixed some missing/incorrect references. o Reintroduced Cache-Control:no-cache to MKCOL responses. C.14. Since -00 o Updated to comply with draft-snell-httpprefer-18. o Reordered "Minimal REPORT Response"Calendaring and"Minimal PROPPATCH Response" sections. o Added some explanatory text to examples. C.15. Since CalConnect XXIV o Updated references. o Stated that "depth-noroot" can be used in conjuctionScheduling Consortium for advice with"return=minimal". o Added text mentioning that "depth-noroot" is based on the MSDN "1,noroot"this specification and"infinity,noroot" Depth header values. o The server behavior required when "return=minimal" would result in zero DAV:propstat elements has been changed from: <?xml version="1.0" encoding="utf-8"?> <D:multistatus xmlns:D="DAV:"> <D:response> <D:href>/container/</D:href> <D:status>HTTP/1.1 200 OK</D:status> </D:response> </D:multistatus>for organizing interoperability testing events tothe slightly more verbose: <?xml version="1.0" encoding="utf-8"?> <D:multistatus xmlns:D="DAV:"> <D:response> <D:href>/container/</D:href> <D:propstat> <D:prop/> <D:status>HTTP/1.1 200 OK</D:status> </D:propstat> </D:response> </D:multistatus>help refine it. Author's Address Kenneth Murchison Carnegie Mellon University 5000 Forbes Avenue Pittsburgh, PA 15213USAUnited States of America Phone:+1 412 268 1982+1-412-268-1982 Email: murch@andrew.cmu.edu