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Versions: 00 01                                                         
WEBDAV Working Group                              J. Stracke, Netscape
INTERNET DRAFT                                         October 5, 1998

Expires April, 1999

                Use of Dublin Core Metadata in WebDAV

Status of this Memo

   This document is an Internet-Draft. 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
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   Distribution of this document is unlimited. Please send comments to
   the Distributed Authoring and Versioning (WEBDAV) working group at
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   Discussions of the WEBDAV working group are archived at


   This document specifies a standard mapping for using the metadata
   vocabulary of Dublin Core ([DUBLIN]) in a WebDAV ([WEBDAV]) server.

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STATUS OF THIS MEMO                             1
ABSTRACT                                        1
CONTENTS                                        2

1 INTRODUCTION                                  2

2 MAPPING                                       3

2.1 NAMESPACE                                   3

2.2 PROPERTY NAMES                              3

2.3 PROPERTY FORMAT                             3

2.4 SUBELEMENTS                                 3


4 SECURITY CONSIDERATIONS                       4

5 IANA CONSIDERATIONS                           4

6 COPYRIGHT                                     4

7 INTELLECTUAL PROPERTY                         5

8 ACKNOWLEDGEMENTS                              5

9 REFERENCES                                    6

9.1 NORMATIVE REFERENCES                        6

9.1 INFORMATIONAL REFERENCES                    6

10 AUTHORS' ADDRESSES                           6

1 Introduction

   This document specifies a standard mapping for using the metadata
   vocabulary of Dublin Core ([DUBLIN]) in a WebDAV ([WEBDAV]) server.

   WebDAV defines a protocol for manipulating metadata on a Web
   resource; in WebDAV, an element of metadata is called a property.
   Dublin Core defines several metadata elements, with standard names
   and standard meanings.  A server which stores Dublin Core metadata
   for its content may wish to make the metadata available as WebDAV
   properties; to forestall the emergence of nonstandard ways to
   provide this functionality, this document defines a standard
   mapping from Dublin Core element labels into WebDAV property names.

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2 Mapping

2.1 Namespace

   WebDAV properties are expressed as XML elements ([XML]), using XML
   namespaces ([XMLNS]) to permit different groups to define sets of
   properties without interfering with each other.  XML namespaces are
   named by URIs.  The Dublin Core datamodel group is defining a
   namespace for XML tags representing Dublin Core elements; WebDAV
   properties should use that same namespace.  The
   URI currently proposed for that namespace is
   <URL:http://purl.org/dc/elements/1.0/>.  Note that this is
   currently only a proposal within the datamodel group; if the Dublin
   Core group as a whole picks a different URI, WebDAV should use that

2.2 Property Names

   A WebDAV property representing a Dublin Core element has the same
   name as the Dublin Core element label.

2.3 Property Format

   Since a WebDAV property can occur on a resource only once, while a
   content item may bear more than one instance of a Dublin Core
   element, some mechanism is needed to represent the multivalued
   elements in the singlevalued property syntax.  The Dublin Core
   datamodel group is working on defining an XML DTD for this
   representation; WebDAV properties should use that DTD when it is

2.4 Subelements

   As of this writing, the Dublin Core group is debating how and
   whether to provide subelements (that is, a technique for
   structuring metadata elements).  Since subelements are not yet
   standardized, this document cannot yet give a definitive answer on
   how to integrate them into WebDAV; a future document may be needed.

   One approach under consideration, set out in [GUENTHER], is to use
   structured element names (e.g., Creator becomes structured into
   Creator.PersonalName and Creator.CorporateName); if this approach
   is adopted, then this document can be applied unchanged, because
   Creator.CorporateName is a perfectly legal XML tag name.
   Alternative approaches could include storing structured data in an
   element; this approach would require a future document specifying a
   mapping from that structure into XML.

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3 Internationalization Considerations

   XML is an inherently internationalizable format, able to express
   any language or character set; as a result, all WebDAV properties,
   including the Dublin Core properties defined here, are

4 Security Considerations

   The security considerations of this mapping are those of [DUBLIN]
   plus those of [WEBDAV].

5 IANA Considerations

   The namespace defined here is isomorphic to the element namespace
   defined in [DUBLIN], so this document introduces no new IANA
   considerations beyond those of [DUBLIN].

6 Copyright

   The following copyright notice is copied from RFC 2026 [Bradner,
   1996], section 10.4, and describes the applicable copyright for this

   Copyright (C) The Internet Society April 5, 1998. All Rights

   This document and translations of it may be copied and furnished to
   others, and derivative works that comment on or otherwise explain it
   or assist in its implementation may be prepared, copied, published
   and distributed, in whole or in part, without restriction of any
   kind, provided that the above copyright notice and this paragraph
   are included on all such copies and derivative works.  However, this
   document itself may not be modified in any way, such as by removing
   the copyright notice or references to the Internet Society or other
   Internet organizations, except as needed for the purpose of
   developing Internet standards in which case the procedures for
   copyrights defined in the Internet Standards process must be
   followed, or as required to translate it into languages other than

   The limited permissions granted above are perpetual and will not be
   revoked by the Internet Society or its successors or assignees.

   This document and the information contained herein is provided on an

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7 Intellectual Property

   The following notice is copied from RFC 2026 [Bradner, 1996],
   section 10.4, and describes the position of the IETF concerning
   intellectual property claims made against this document.

   The IETF takes no position regarding the validity or scope of any
   intellectual property or other rights that might be claimed to
   pertain to the implementation or use other technology described in
   this document or the extent to which any license under such rights
   might or might not be available; neither does it represent that it
   has made any effort to identify any such rights.  Information on the
   IETF's procedures with respect to rights in standards-track and
   standards-related documentation can be found in BCP-11.  Copies of
   claims of rights made available for publication 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 implementors or users of this specification
   can be obtained from the IETF Secretariat.

   The IETF invites any interested party to bring to its attention any
   copyrights, patents or patent applications, or other proprietary
   rights which may cover technology that may be required to practice
   this standard.  Please address the information to the IETF Executive

8 Acknowledgements

   The triviality of this specification is due to the hard work put
   into [WEBDAV], [DUBLIN], [XML], and [XMLNS] by their respective
   authors and working groups.

   The need for this specification was pointed out (by Jim Whitehead,
   I think) during the variants discussion held after a meeting of the
   versioning design team of the WebDAV working group.

   Thanks to Liz Parrot for alerting me to the question of

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9 References

9.1 Normative References

   [DUBLIN] S. Weibel, J. Kunze, C. Lagoze, M. Wolf, "Dublin Core
   Metadata for Resource Discovery."  RFC 2413.  Online Computer
   Library Center; University of California, San Francisco; Cornell;
   Reuters.  September, 1998.

   [WEBDAV] Y. Y. Goland, E. J. Whitehead, Jr., A.  Faizi,
   S. R. Carter, D. Jensen, "Extensions for Distributed Authoring on
   the World Wide Web - WebDAV."
   Draft-ietf-webdav-protocol-08. Internet Draft, work in progress.
   Microsoft, U.C. Irvine, Netscape, Novell. April, 1998.

   [XML] T. Bray, J. Paoli, C. M.  Sperberg-McQueen, "Extensible
   Markup Language (XML)." World Wide Web Consortium Recommendation
   REC-xml-19980210.  <http://www.w3.org/TR/1998/REC-xml-19980210>.

9.2 Informational References

   [XMLNS] T. Bray, D. Hollander, A. Layman, "Name Spaces in XML"
   World Wide Web Consortium Working Draft,

   [GUENTHER] R. Guenther, "Dublin Core Qualifiers/Substructure",
   <http://www.loc.gov/marc/dcqualif.html>.  October, 1997.


   J. Stracke
   Netscape Communications Corporation
   501 E. Middlefield Rd.
   Mountain View, CA  94043
   Email: francis@netscape.com

Stracke                                                       [Page 6]