DCMI Specifications

Semantic Recommendations

DCMI Metadata Terms [DCMI Recommendation]. This periodically updated document provides a one-stop source of up-to-date information on DCMI metadata terms, including the classic Dublin Core Metadata Element Set, the DCMI Type Vocabulary, and resource classes used as formal domains and ranges. Supporting documents includes

• DCMI Namespace Policy [DCMI Recommendation]. This document describes how metadata terms are assigned URIs by DCMI and the policies governing changes to the documented meanings associated with those URIs.
• DCMI term declarations represented in RDF schema language. Since 2001, DCMI term declarations have been published as Web documents (with the status DCMI Recommendation) and, in parallel, as machine-processable RDF/XML documents.
• The Dublin Core Metadata Registry [DCMI Recommended Resource]. This application, hosted at the University of Tsukuba as a service for the DCMI community, provides a navigational interface to DCMI's machine-processable RDF term declarations. The registry is under development as an open-source software project.
• Dublin Core Metadata Element Set [DCMI Recommendation]. This document excerpts from DCMI Metadata Terms the fifteen elements of the classic "Dublin Core", which has been standardized as ISO Standard 15836:2009.

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User guidelines

Interoperability Levels for Dublin Core Metadata [DCMI Recommended Resource]. This document articulates current thinking in the Dublin Core community about the nature of metadata interoperability. Read more...

Guidelines for Dublin Core Application Profiles [DCMI Recommended Resource]. This document provides guidelines for the creation of Dublin Core Application Profiles. The document explains the key components of a Dublin Core Application Profile and walks through the process of developing a profile. The document is aimed at designers of application profiles -- people who will bring together metadata terms for use in a specific context.

Singapore Framework for Dublin Core Application Profiles [DCMI Recommended Resource]. The Singapore Framework for Dublin Core Application Profiles is a framework for designing metadata applications for maximum interoperability and for documenting such applications for maximum reusability. The framework defines a set of descriptive components that are necessary or useful for documenting an Application Profile and describes how these documentary standards relate to standard domain models and Semantic Web foundation standards. The framework forms a basis for reviewing Application Profiles for documentary completeness and for conformance with Web-architectural principles.

Using Dublin Core [DCMI Recommended Resource]. From January 1998 through the latest version in November 2005, this document was maintained as the main entry point for new users of Dublin Core metadata. While this document is accessibly written, with useful concrete examples, readers should be aware that the document is by now somewhat out of date and is best used in conjunction with Guidelines for Dublin Core Application Profiles.

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Model-related specifications

DCMI Abstract Model [DCMI Recommendation]. This document specifies an abstract syntax for "description sets" (metadata records). Finalized as a DCMI Recommendation in March 2005, the DCMI Abstract Model (DC-AM) expressed the style of metadata that had emerged in the Dublin Core community over the previous decade as formal constructs based on the W3C Resource Description Framework (for example, by giving a formal definition to the DC-specific notion of a "vocabulary encoding scheme" and providing for the use of parallel labels in multiple languages). The Abstract Model was designed to bridge the modern paradigm of the unbounded, linked data graph and the more familiar paradigm of the validatable metadata record, providing a foundation for the development of application-independent syntax specifications and constraint languages.

Description Set Profiles: A constraint language for Dublin Core Application Profiles [DCMI Working Draft]. This document specifies an application-independent language for the constraints used in defining "templates" for metadata records -- for example, to specify a template for records which describe exactly "one book", with "up to ten authors", using "subject headings from the Library of Congress". This specification represents work in progress and is likely to evolve in response to implementation experience.

Criteria for the Review of Application Profiles [DCMI Recommended Resource]. This document was developed by the DCMI Usage Board to evaluate Application Profiles for documentary completeness and for conformance with linked-data principles. The criteria are based on the DCMI Abstract Model, Description Set Profile (DSP) language, and Singapore Framework. Even when conformance with these specifications is not a requirement, implementers may find these review criteria useful for uncovering flaws or weaknesses in the logic of an application profile.

A MoinMoin Wiki Syntax for Description Set Profiles [DCMI Working Draft]. Using this draft syntax, editors can embed formal constraint information about application profiles into normal Wiki documents and extract this information using an Open Source MoinMoin Wiki tool into an XML representation. This functionality is illustrated by the MoinMoin Wiki document for the Scholarly Works Application Profile.

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Syntax guidelines

DC-TEXT [DCMI Recommended Resource]. "Expressing Dublin Core metadata using the DC-Text format" is a syntax for representing a DC-AM Description Set in plain text. Its primary use is in presenting metadata constructs for human consumption.

DC-HTML [DCMI Recommendation]. "Expressing Dublin Core metadata using HTML/XHTML meta and link elements" describes how a Dublin Core metadata description set can be encoded using the HTML/XHTML <meta> and <link> elements. This specification is also an HTML "meta data profile" as defined by the HTML specification. See also:

• RDFa, another syntax for embedding Dublin Core descriptions in Web pages, which became a W3C Recommendation in October 2008 and has strong tool support in platforms such as Drupal and Yahoo's Search Monkey.
• The predecessor specification for DC-HTML, DCQ-HTML (last updated in 2003), consistently remains one of the most-accessed documents on the DCMI Web site despite its clearly marked status as a "Superseded Recommendation". Early versions of this specifications used the so-called "dotty" syntax for appending an additional "qualifier" to an element name. as with "DC.Coverage.temporal" -- an encoding style that is now discouraged. This and other related issues are discussed in "Notes on DCMI specifications for Dublin Core metadata in HTML/XHTML meta and link elements".

DC-DS-XML [Proposed Recommendation]. "Expressing Dublin Core Description Sets using XML (DC-DS-XML)" specifies an XML format for representing a Dublin Core metadata description set. The specification supports all of the features of a Description Set as described by the DCMI Abstract Model. Related resources include:

• Notes on DC-DS-XML XML Format, which describes the development of the format and its relationship to the 2003 specification, DC-XML-GUIDELINES.
• DC-XML-GUIDELINES [DCMI Recommendation]. The specification "Guidelines for implementing Dublin Core in XML" of April 2003 has been used in numerous implementations and remains popular despite its well-described limitations (see above). XMLS schemas implementing the 2003 encoding conventions are available in several variants.

DC-RDF [DCMI Recommendation]. "Expressing Dublin Core metadata using the Resource Description Framework (RDF)" describes how constructs of the DCMI Abstract Model may be expressed in RDF graphs. How this document relates to earlier styles for expressing Dublin Core metadata in RDF is discussed in "Notes on DCMI specifications for Dublin Core metadata in RDF".