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DCMI Metadata Terms

Table of Contents

1. Introduction and Definitions
2. Properties in the /terms/ namespace
3. Properties in the legacy /elements/1.1/ namespace
4. Vocabulary Encoding Schemes
5. Syntax Encoding Schemes
6. Classes
7. DCMI Type Vocabulary
8. Terms related to the DCMI Abstract Model

Index of Terms

Section 1: Introduction and Definitions

This document is an up-to-date, authoritative specification of all metadata terms maintained by the Dublin Core Metadata Initiative. Included are the fifteen terms of the Dublin Core Metadata Element Set, which have also been published as IETF RFC 5013 [RFC5013], ANSI/NISO Standard Z39.85-2007 [NISOZ3985], and ISO Standard 15836-21003 [ISO15836]. RDF Schema versions of the DCMI term declarations are available at [RDFSCHEMAS].

Each term is specified with the following minimal set of attributes:

Where applicable, the following attributes provide additional information about a term:

This documentation is maintained by the DCMI Usage Board in accordance with the DCMI Namespace Policy [NAMESPACE]. The namespace policy says that DCMI terms are identified using Uniform Resource Identifiers (URIs). In accordance with the principle that distinct URIs should be assigned to distinct resources, the policy sets limits on the range of editorial changes that may allowably be made to the official labels, definitions, and usage comments associated with DCMI terms. By policy, any changes of meaning judged "likely to have a substantial impact on either machine processing of DCMI terms or the functional semantics of the terms" must trigger the creation of a new, distinct term with a new, distinct URI. For further information about the change history and the corresponding Usage Board decisions, please consult the document "DCMI Metadata Terms: A complete historical record" [HISTORY].

The current release of "DCMI Metadata Terms" reflects editorial changes approved since December 2006, notably:

• improved definitions, descriptive labels, and usage comments,
• differentiation of Encoding Schemes between Syntax Encoding Schemes and Vocabulary Encoding Schemes, with clarified definitions,
• updated references to standards maintained by the Internet Engineering Task Force and the International Organization for Standardization (ISO),
• two new terms related to the DCMI Abstract Model [DCAM],
• clarification in the DCMI Abstract Model that a Vocabulary Encoding Scheme is an "enumerated set of resources" (such as the DCMI Type Vocabulary, a set of classes), and
• the specification of formal domains and ranges (and in some cases, subproperty relations) for DCMI properties, as discussed below.

Formal domains and ranges specify what kind of described resources and value resources are associated with a given property. Domains and ranges express the meanings implicit in natural-language definitions in an explicit form that is usable for the automatic processing of logical inferences. When a given property is encountered, an inferencing application may use the domains and ranges assigned by DCMI to that property in order to make inferences about the resources described thereby.

So as not to affect the conformance of existing implementations of "simple Dublin Core" in RDF, domains and ranges have not been specified for the fifteen properties of the dc: namespace (http://purl.org/dc/elements/1.1/). Rather, fifteen new properties with "names" identical to those of DCMES Version 1.1 have been created in the dcterms: namespace (http://purl.org/dc/terms/). These fifteen new properties have been defined as subproperties of the corresponding properties of DCMES Version 1.1 and assigned domains and ranges as outlined in this document.

Implementers may freely choose to use these fifteen properties either in their legacy dc: variant (e.g., http://purl.org/dc/elements/1.1/creator) or in the dcterms: variant (e.g., http://purl.org/dc/terms/creator) depending on application requirements. The RDF schemas of the DCMI namespaces describe the subproperty relation of dcterms:creator to dc:creator for use by Semantic Web-aware applications. Over time, however, implementers are encouraged to use the semantically more precise dcterms: properties, as they more fully follow emerging notions of best practice for machine-processable metadata.

This document reflects the terminology used in the revised DCMI Abstract Model approved as a DCMI Recommendation in 2007 [DCAM]. A table comparing the two terminologies is presented below.

DCMI maintains a Web page with pointers to known translations of semantic specifications and related DCMI documents [TRANSLATIONS]

References

Section 2: Properties in the /terms/ namespace

Section 3: Properties in the legacy /elements/1.1/ namespace

Section 4: Vocabulary Encoding Schemes

Section 5: Syntax Encoding Schemes

Section 6: Classes

Section 7: DCMI Type Vocabulary

Section 8: Terms related to the DCMI Abstract Model