The Dublin Core Metadata Element Set

Status of This Memo

This memo provides information for the Internet community. It does not specify an Internet standard of any kind. Distribution of this memo is unlimited.

Abstract

This document defines fifteen metadata elements for resource description in a cross-disciplinary information environment.

1. Introduction

The Dublin Core Metadata Workshop Series began in 1995 with an invitational workshop that brought together librarians, digital library researchers, content experts, and text-markup experts to promote better discovery standards for electronic resources. The resulting metadata element set defines fifteen metadata elements for resource description in a cross-disciplinary information environment.

This document contains the current text of Dublin Core "Version 1.1". Version 1.1 is the basis of ANSI/NISO Z39.85-2001 [Z39.85]. The text in the present RFC closely follows the text in the 2007 revision of ANSI/NISO Z39.85, especially Sections 2-6 and 10-12 [Z39.85-2007]. The present RFC obsoletes RFC 2413 [RFC2413], which was the first published version of the Dublin Core ("Version 1.0"). The main differences between the present RFC and RFC 2413 are in the wording of definitions -- for Contributor and Date (semantically broadened), for Relation (clarified), and in the general removing of redundant references to "the content of" a resource. In addition, the present RFC recommends lowercase element names (consistent with RDF property types), remains silent about the unrestrictedness of element ordering and repeatability (application profiles being the proper place to discuss such topics), and references the current abstract model, vocabularies, and namespace policies in which the Dublin Core is embedded.

2. Foreword

The Dublin Core Metadata Element Set is a vocabulary of fifteen properties for use in resource description. The name "Dublin" is due to its origin at a 1995 invitational workshop in Dublin, Ohio; "core" because its elements are broad and generic, usable for describing a wide range of resources.

The fifteen element "Dublin Core" described in this document is part of a larger set of metadata vocabularies and technical specifications maintained by the Dublin Core Metadata Initiative (DCMI). The full set of vocabularies, DCMI Metadata Terms [DCTERMS], also includes a set of resource classes, the DCMI Type Vocabulary [DCTYPE]. The terms in DCMI vocabularies are intended to be used in combination with terms from other compatible vocabularies in the context of application profiles and on the basis of the DCMI Abstract Model [DCAM].

All changes made to terms of the Dublin Core Metadata Element Set since 2001 have been reviewed by a DCMI Usage Board in the context of a DCMI Namespace Policy [DCNMSPC]. The namespace policy describes how DCMI terms are assigned Uniform Resource Identifiers (URIs) and sets limits on the range of editorial changes that may allowably be made to the labels, definitions, and usage comments associated with existing DCMI terms.

3. Scope and Purpose

The Dublin Core Metadata Element Set is a standard for cross-domain resource description. As in RFC 3986 [RFC3986], "Uniform Resource Identifier (URI): Generic Syntax", this specification does not limit the scope of what might be a resource.

The elements described in this document are typically used in the context of an application profile which constrains or specifies their use in accordance with local or community-based requirements and policies. The specification of such implementation detail is outside the scope of this document.

4. Definitions

DCMI -- the Dublin Core Metadata Initiative, maintenance agency for Dublin Core Metadata Element Set.

Resource -- anything that might be identified (the same definition as in RFC 3986 and in the DCMI Abstract Model).

Lifecycle of a resource -- a sequence of events that mark the development and use of a resource. Some examples of events in a lifecycle are: conception of an invention, creation of a draft, revision of an article, publication of a book, acquisition by a library, transcription to magnetic disk, migration to optical storage, translation into English, and derivation of a new work (e.g., a movie).

5. The Element Set

In the element descriptions below, each element has a descriptive label ("label") for human consumption and a unique token ("name") for use in machine processing.

In accordance with the DCMI Namespace Policy [DCNMSPC], the "name" of an element is appended to a DCMI namespace URI to construct a Uniform Resource Identifier as a globally unique identifier for that element. The use of element names and URIs in the context of different implementation technologies is explained in DCMI Encoding Guidelines [DCENCOD].

6. The Elements

Element Name: title

   Label:       Title
   Definition:  A name given to the resource.

Element Name: creator

   Label:       Creator
   Definition:  An entity primarily responsible for making the resource.
   Comment:     Examples of a Creator include a person, an organization,
   
                or a service.  Typically, the name of a Creator should
                be used to indicate the entity.

Element Name: subject

   Label:       Subject
   Definition:  The topic of the resource.
   Comment:     Typically, the subject will be represented using
                keywords, key phrases, or classification codes.
                Recommended best practice is to use a controlled
                vocabulary.  To describe the spatial or temporal
                topic of the resource, use the Coverage element.

Element Name: description

   Label:       Description
   Definition:  An account of the resource.
   Comment:     Description may include but is not limited to:
                an abstract, a table of contents, a graphical
                representation, or a free-text account of
                the resource.

Element Name: publisher

   Label:       Publisher
   Definition:  An entity responsible for making the resource available.
   Comment:     Examples of a Publisher include a person, an
                organization, or a service.  Typically, the name of
                a Publisher should be used to indicate the entity.

Element Name: contributor

   Label:       Contributor
   Definition:  An entity responsible for making contributions to the
                resource.
   Comment:     Examples of a Contributor include a person, an
                organization, or a service.  Typically, the name of a
                Contributor should be used to indicate the entity.

Element Name: date

   Label:       Date
   Definition:  A point or period of time associated with an event
                in the lifecycle of the resource.
   Comment:     Date may be used to express temporal information
                at any level of granularity.  Recommended best
                practice is to use an encoding scheme, such as
                the W3CDTF profile of ISO 8601 [W3CDTF].

Element Name: type

   Label:       Type
   Definition:  The nature or genre of the resource.
   Comment:     Recommended best practice is to use a controlled
                vocabulary such as the DCMI Type Vocabulary
                [DCTYPE].  To describe the file format, physical medium,
                or dimensions of the resource, use the Format element.

Element Name: format

   Label:       Format
   Definition:  The file format, physical medium, or dimensions
                of the resource.
   Comment:     Examples of dimensions include size and duration.
                Recommended best practice is to use a controlled
                vocabulary such as the list of Internet Media Types
                [MIME].

Element Name: identifier

   Label:       Identifier
   Definition:  An unambiguous reference to the resource within a given
                context.
   Comment:     Recommended best practice is to identify the
                resource by means of a string conforming
                to a formal identification system.

Element Name: source

   Label:       Source
   Definition:  A related resource from which the described resource
                is derived.
   Comment:     The described resource may be derived from the
                related resource in whole or in part.  Recommended
                best practice is to identify the related resource
                by means of a string conforming to a formal
                identification system.

Element Name: language

   Label:       Language
   Definition:  A language of the resource.
   Comment:     Recommended best practice is to use a controlled
                vocabulary such as RFC 4646 [RFC4646].

Element Name: relation

   Label:       Relation
   Definition:  A related resource.
   Comment:     Recommended best practice is to identify the
                related resource by means of a string conforming
                to a formal identification system.

Element Name: coverage

   Label:       Coverage
   Definition:  The spatial or temporal topic of the resource, the
                spatial applicability of the resource, or the
                jurisdiction under which the resource is relevant.
   Comment:     Spatial topic and spatial applicability may be a named
                place or a location specified by its geographic
                coordinates.  Temporal topic may be a named period,
                date, or date range.  A jurisdiction may be a named
                administrative entity or a geographic place to which the
                resource applies.  Recommended best practice is to use a
                controlled vocabulary such as the Thesaurus of
                Geographic Names [TGN].  Where appropriate, named places
                or time periods can be used in preference to numeric
                identifiers such as sets of coordinates or date ranges.

Element Name: rights

   Label:       Rights
   Definition:  Information about rights held in and over the resource.
   Comment:     Typically, rights information includes a statement about
                various property rights associated with the resource,
                including intellectual property rights.

7. Security Considerations

The Dublin Core element set poses no risk to computers and networks. It poses minimal risk to searchers who obtain incorrect or private information due to careless mapping from rich data descriptions to the Dublin Core elements. No other security concerns are likely.

10. Informative References

   [DCAM]        DCMI Abstract Model.
                 http://dublincore.org/documents/abstract-model/
   
   [DCENCOD]     DCMI Encoding Guidelines.
                 http://dublincore.org/resources/expressions/
   
   [DCNMSPC]     DCMI Namespace Policy.
                 http://dublincore.org/documents/dcmi-namespace/
   
   [DCTERMS]     DCMI Metadata Terms.
                 http://dublincore.org/documents/dcmi-terms/
   
   [DCTYPE]      DCMI Type Vocabulary.
                 http://dublincore.org/documents/dcmi-type-vocabulary/
   
   [ISO3166]     ISO 3166 - Codes for the representation of names of
                 countries.  http://www.din.de/
   
   [MIME]        Internet Media Types.
                 http://www.iana.org/assignments/media-types/
   
   [RDF]         Resource Description Framework.  http://www.w3.org/RDF/
   
   [RFC2413]     Weibel, S., Kunze, J., Lagoze, C., and M. Wolf, "Dublin
                 Core Metadata for Resource Discovery", RFC 2413,
                 September 1998.
   
   [RFC2731]     Kunze, J., "Encoding Dublin Core Metadata in HTML", RFC
                 2731, December 1999.
   
   [RFC3986]     Berners-Lee, T., Fielding, R., and L. Masinter,
                 "Uniform Resource Identifier (URI): Generic Syntax",
                 STD 66, RFC 3986, January 2005.
   
   [RFC4646]     Phillips, A. and M. Davis, "Tags for Identifying
                 Languages", BCP 47, RFC 4646, September 2006.
   
   [TGN]         Getty Thesaurus of Geographic Names.
                 http://www.getty.edu/research/tools/vocabulary/
                 tgn/index.html
   
   [W3CDTF]      Date and Time Formats, W3C Note.
                 http://www.w3.org/TR/NOTE-datetime
   
   [Z39.85]      ANSI/NISO Standard Z39.85-2001 - The Dublin Core
                 Metadata Element Set.
                 http://www.niso.org/standards/resources/Z39-85.pdf
   
   [Z39.85-2007] ANSI/NISO Standard Z39.85-2007 - The Dublin Core
                 Metadata Element Set.
                 http://www.niso.org/standards/resources/Z39-85-2007.pdf

Appendix A: Further Reading

(This appendix is not part of the Z39.85 standard. It is included for information only.)

Further information about the Dublin Core metadata element set is available at the URL,

       http://dublincore.org/

This Web site contains information about workshops, reports, working group papers, projects, and new developments concerning the Dublin Core Metadata Initiative (DCMI).

Appendix B: Maintenance Agency

(This appendix is not part of the Z39.85 standard. It is included for information only.)

The Dublin Core Metadata Initiative (DCMI) is responsible for the development, standardization, and promotion of the Dublin Core metadata element set. Information on DCMI is available at the URL,

       http://dublincore.org/

Authors' Addresses

   John A. Kunze
   California Digital Library
   University of California, Office of the President
   415 20th St, 4th Floor
   Oakland, CA  94612-3550, USA
   
   Fax:   +1 510-893-5212
   EMail: jak@ucop.edu
   
   Thomas Baker
   Director, Specifications and Documentation
   Dublin Core Metadata Initiative
   c/o OCLC Research
   Dublin, OH  43017, USA

EMail:

          tbaker@tbaker.de

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