220px, Logo image of DCMI, which formulates Dublin Core
The Dublin Core, also known as the Dublin Core Metadata Element Set (DCMES), is a set of fifteen "core" elements (properties) for describing resources. This fifteen-element Dublin Core has been formally standardized as ISO 15836, ANSI/NISO Z39.85, and IETF RFC 5013. The Dublin Core Metadata Initiative (DCMI), which formulates the Dublin
Core, is a project of the
Association for Information Science and Technology (ASIS&T), a non-profit organization. The core properties are part of a larger set of DCMI Metadata Terms. "Dublin Core" is also used as an adjective for Dublin Core metadata, a style of
metadata
Metadata is "data that provides information about other data", but not the content of the data, such as the text of a message or the image itself. There are many distinct types of metadata, including:
* Descriptive metadata – the descriptive ...
that draws on multiple
Resource Description Framework The Resource Description Framework (RDF) is a World Wide Web Consortium (W3C) standard originally designed as a data model for metadata. It has come to be used as a general method for description and exchange of graph data. RDF provides a variety of ...
(RDF) vocabularies, packaged and constrained in Dublin Core application profiles.
The resources described using the Dublin Core may be digital resources (video, images, web pages, etc.) as well as physical resources such as books or works of art.
Dublin Core metadata may be used for multiple purposes, from simple resource description to combining metadata vocabularies of different
metadata standards, to providing interoperability for metadata vocabularies in the
linked data
In computing, linked data (often capitalized as Linked Data) is structured data which is interlinked with other data so it becomes more useful through semantic queries. It builds upon standard Web technologies such as HTTP, RDF and URIs, but ...
cloud and
Semantic Web implementations.
Background
"Dublin" refers to
Dublin, Ohio, USA where the schema originated during the 1995 invitational OCLC/NCSA Metadata Workshop, hosted by the
OCLC
OCLC, Inc., doing business as OCLC, See also: is an American nonprofit cooperative organization "that provides shared technology services, original research, and community programs for its membership and the library community at large". It wa ...
(known at that time as Online Computer Library Center), a library consortium based in Dublin, and the
National Center for Supercomputing Applications (NCSA). "Core" refers to the metadata terms as "broad and generic being usable for describing a wide range of resources".
The semantics of Dublin Core were established and are maintained by an international, cross-disciplinary group of professionals from
librarianship,
computer science
Computer science is the study of computation, automation, and information. Computer science spans theoretical disciplines (such as algorithms, theory of computation, information theory, and automation) to Applied science, practical discipli ...
,
text encoding,
museum
A museum ( ; plural museums or, rarely, musea) is a building or institution that cares for and displays a collection of artifacts and other objects of artistic, cultural, historical, or scientific importance. Many public museums make th ...
s, and other related fields of scholarship and practice.
In 1999, the first Dublin Core encoding standard was in HTML. Starting in 2000, the Dublin Core community focused on "
application profile In the information sciences, an application profile consists of a set of metadata elements, policies, and guidelines defined for a particular application.
The elements may come from one or more element sets, thus allowing a given application to m ...
s" – the idea that metadata records would use Dublin Core together with other specialized vocabularies to meet particular implementation requirements. During that time, the World Wide Web Consortium's work on a generic
data model for metadata, the
Resource Description Framework The Resource Description Framework (RDF) is a World Wide Web Consortium (W3C) standard originally designed as a data model for metadata. It has come to be used as a general method for description and exchange of graph data. RDF provides a variety of ...
(RDF), was maturing. As part of an extended set of DCMI metadata terms, Dublin Core became one of the most popular vocabularies for use with RDF, more recently in the context of the
linked data
In computing, linked data (often capitalized as Linked Data) is structured data which is interlinked with other data so it becomes more useful through semantic queries. It builds upon standard Web technologies such as HTTP, RDF and URIs, but ...
movement.
The Dublin Core Metadata Initiative (DCMI) provides an open forum for the development of interoperable online
metadata standards for a broad range of purposes and of business models. DCMI's activities include consensus-driven working groups, global conferences and workshops, standards liaison, and educational efforts to promote widespread acceptance of metadata standards and practices. In 2008, DCMI separated from OCLC and incorporated as an independent entity.
Currently, any and all changes that are made to the Dublin Core standard, are reviewed by a DCMI Usage Board within the context of a DCMI Namespace Policy (DCMI-NAMESPACE). This policy describes how terms are assigned and also sets limits on the amount of editorial changes allowed to the labels, definitions, and usage comments.
Levels of the standard
The Dublin Core standard originally included two levels: Simple and Qualified. ''Simple Dublin Core'' comprised 15 elements; ''Qualified Dublin Core'' included three additional elements (Audience, Provenance and RightsHolder), as well as a group of element refinements (also called qualifiers) that could refine the semantics of the elements in ways that may be useful in resource discovery.
Since 2012, the two have been incorporated into the ''DCMI Metadata Terms'' as a single set of terms using the
RDF data model.
The full set of elements is found under the namespace http://purl.org/dc/terms/. Because the definition of the terms often contains domains and ranges, which may not be compatible with the pre-RDF definitions used for the original 15 Dublin Core elements, there is a separate namespace for the original 15 elements as previously defined: http://purl.org/dc/elements/1.1/.
Dublin Core Metadata Element Set
The original DCMES Version 1.1 consists of 15 metadata elements, defined this way in the original specification:
# Contributor – "An entity responsible for making contributions to the resource".
# Coverage – "The spatial or temporal topic of the resource, the spatial applicability of the resource, or the jurisdiction under which the resource is relevant".
# Creator – "An entity primarily responsible for making the resource".
# Date – "A point or period of time associated with an event in the lifecycle of the resource".
# Description – "An account of the resource".
# Format – "The file format, physical medium, or dimensions of the resource".
# Identifier – "An unambiguous reference to the resource within a given context".
# Language – "A language of the resource".
# Publisher – "An entity responsible for making the resource available".
# Relation – "A related resource".
# Rights – "Information about rights held in and over the resource".
# Source – "A related resource from which the described resource is derived".
# Subject – "The topic of the resource".
# Title – "A name given to the resource".
# Type – "The nature or genre of the resource".
Each Dublin Core element is optional and may be repeated. The DCMI has established standard ways to refine elements and encourage the use of encoding and vocabulary schemes. There is no prescribed order in Dublin Core for presenting or using the elements. The Dublin Core became a NISO standards, Z39.85, and IETF RFC 5013 in 2007, ISO 15836 standard in 2009 and is used as a base-level data element set for the description of learning resources in the
ISO/IEC 19788-2 Metadata for learning resources (MLR) – Part 2: Dublin Core elements, prepared by the
ISO/IEC JTC 1/SC 36 ISO/IEC JTC 1/SC 36 Information Technology for Learning, Education and Training is a standardization subcommittee (SC), which is part of the Joint Technical Committee ISO/IEC JTC 1 of the International Organization for Standardization (ISO) and the ...
.
Full information on element definitions and term relationships can be found in the Dublin Core Metadata Registry.
Encoding examples
:
:
:
:
Example of use nd mentionby WebCite
On the "archive form" web page for
WebCite it says,
in part: "Metadata (optional): These are Dublin Core elements.
...
Qualified Dublin Core
(Superseded in 2008 by the DCMI Metadata Terms.) Subsequent to the specification of the original 15 elements, an ongoing process to develop exemplary terms extending or refining the DCMES was begun. The additional terms were identified, generally in working groups of the DCMI, and judged by the DCMI Usage Board to be in conformance with principles of good practice for the qualification of Dublin Core metadata elements.
Element refinements make the meaning of an element narrower or more specific. A refined element shares the meaning of the unqualified element, but with a more restricted scope. The guiding principle for the qualification of Dublin Core elements, colloquially known as the ''Dumb-Down Principle'', states that an application that does not understand a specific element refinement term should be able to ignore the qualifier and treat the metadata value as if it were an unqualified (broader) element. While this may result in some loss of specificity, the remaining element value (without the qualifier) should continue to be generally correct and useful for discovery.
In addition to element refinements, Qualified Dublin Core includes a set of recommended encoding schemes, designed to aid in the interpretation of an element value. These schemes include
controlled vocabularies and formal notations or parsing rules. A value expressed using an encoding scheme may thus be a token selected from a controlled vocabulary (for example, a term from a classification system or set of subject headings) or a string formatted in accordance with a formal notation, for example, "2000-12-31" as the ISO standard expression of a date. If an encoding scheme is not understood by an application, the value may still be useful to a ''human reader''.
Audience, Provenance and RightsHolder are elements, but not part of the Simple Dublin Core 15 elements. Use Audience, Provenance and RightsHolder only when using Qualified Dublin Core. DCMI also maintains a small, general vocabulary recommended for use within the element Type. This vocabulary currently consists of 12 terms.
DCMI Metadata Terms
The DCMI Metadata Terms lists the current set of the Dublin Core vocabulary.
This set includes the fifteen terms of the DCMES (in ''italic''), as well as the qualified terms. Each term has a unique URI in the namespace http://purl.org/dc/terms, and all are defined as
RDF properties.
Syntax
Syntax choices for metadata expressed with the Dublin Core elements depend on context. Dublin Core concepts and semantics are designed to be syntax independent and apply to a variety of contexts, as long as the metadata is in a form suitable for interpretation by both machines and people.
The Dublin Core Abstract Model provides a reference model against which particular Dublin Core encoding guidelines can be compared, independent of any particular encoding syntax. Such a reference model helps implementers get a better understanding of the kinds of descriptions they are trying to encode and facilitates the development of better mappings and translations between different syntaxes.
Notable applications
One
Document Type Definition
A document type definition (DTD) is a set of ''markup declarations'' that define a ''document type'' for an SGML-family markup language ( GML, SGML, XML, HTML).
A DTD defines the valid building blocks of an XML document. It defines the document s ...
based on Dublin Core is the Open Source Metadata Framework (OMF) specification. OMF is in turn used by
Rarian (superseding
ScrollKeeper
ScrollKeeper is a document cataloging system. It manages documentation metadata, as specified by the Open Source Metadata Framework (OMF). ScrollKeeper was used by the GNOME desktop help browser, Yelp, but has since been replaced by Rarian.ht ...
), which is used by the
GNOME
A gnome is a mythological creature and diminutive spirit in Renaissance magic and alchemy, first introduced by Paracelsus in the 16th century and later adopted by more recent authors including those of modern fantasy literature. Its characte ...
desktop and
KDE help browsers and the ScrollServer documentation server.
PBCore is also based on Dublin Core. The
Zope CMF's Metadata products, used by the
Plone,
ERP5, the Nuxeo CPS
Content management system
A content management system (CMS) is computer software used to manage the creation and modification of digital content ( content management).''Managing Enterprise Content: A Unified Content Strategy''. Ann Rockley, Pamela Kostur, Steve Manning. New ...
s,
SimpleDL
SimpleDL is digital collection management software that allows for the upload, description, management and access of digital collections. In addition to that, it is UTF-8 compatible. SimpleDL is not limited by format and is capable of handling doc ...
, and
Fedora Commons
Fedora (or Flexible Extensible Digital Object Repository Architecture) is a digital asset management (DAM) content repository architecture upon which institutional repositories, digital archives, and digital library systems might be built. Fed ...
also implement Dublin Core. The
EPUB
EPUB is an e-book file format that uses the ".epub" file extension. The term is short for ''electronic publication'' and is sometimes styled ''ePub''. EPUB is supported by many e-readers, and compatible software is available for most smartpho ...
e-book
An ebook (short for electronic book), also known as an e-book or eBook, is a book publication made available in digital form, consisting of text, images, or both, readable on the flat-panel display of computers or other electronic devices. A ...
format uses Dublin Core metadata in the
OPF file.
The
Australian Government Locator Service (AGLS) metadata standard is an application profile of Dublin Core.
See also
*
Metadata registry
*
Metadata Object Description Schema
The Metadata Object Description Schema (MODS) is an XML-based bibliographic description schema developed by the United States Library of Congress' Network Development and Standards Office. MODS was designed as a compromise between the complexity ...
*
Ontology (information science)
In computer science and information science, an ontology encompasses a representation, formal naming, and definition of the categories, properties, and relations between the concepts, data, and entities that substantiate one, many, or all domains ...
*
Open Archives Initiative (OAI)
*
Controlled vocabulary
Control may refer to:
Basic meanings Economics and business
* Control (management), an element of management
* Control, an element of management accounting
* Comptroller (or controller), a senior financial officer in an organization
* Control ...
*
Interoperability
Interoperability is a characteristic of a product or system to work with other products or systems. While the term was initially defined for information technology or systems engineering services to allow for information exchange, a broader defi ...
*
Asset Description Metadata SchemaADMS, a metadata standard maintained by the
W3C for describing semantic standards. Implemented on
Joinup
Joinup is a collaboration platform created by the European Commission. It is funded by the European Union via its
Interoperability Solutions for Public Administrations Programme (ISA Programme).
Joinup was launched on 9 December 2011. It replac ...
.
*
Metadata Encoding and Transmission Standard (METS), maintained by the
Library of Congress
The Library of Congress (LOC) is the research library that officially serves the United States Congress and is the ''de facto'' national library of the United States. It is the oldest federal cultural institution in the country. The libra ...
for the
Digital Library Federation
*
Preservation Metadata: Implementation Strategies (PREMIS)
*
Darwin Core
Darwin Core (often abbreviated to DwC) is an extension of Dublin Core for biodiversity informatics. It is meant to provide a stable standard reference for sharing information on biological diversity (biodiversity). The terms described in this stan ...
, a Dublin Core extension for biodiversity informatics
Related software
*
Fedora
A fedora () is a hat with a soft brim and indented crown.Kilgour, Ruth Edwards (1958). ''A Pageant of Hats Ancient and Modern''. R. M. McBride Company. It is typically creased lengthwise down the crown and "pinched" near the front on both side ...
, a
digital asset management (DAM) architecture capable of implementing
OAI-PMH (thus, also Dublin Core).
*
Omeka
Omeka (also known as Omeka Classic) is a free, open-source content management system for online digital collections. As a web application, it allows users to publish and exhibit cultural heritage objects, and extend its functionality with themes ...
, a free and open source
content management system
A content management system (CMS) is computer software used to manage the creation and modification of digital content ( content management).''Managing Enterprise Content: A Unified Content Strategy''. Ann Rockley, Pamela Kostur, Steve Manning. New ...
using an unqualified Dublin Core metadata standard.
References
Further reading
*
Dublin Core presentation by Luca Dini, lecturer at the
Free University of Bozen-Bolzano
External links
*
Dublin Core Metadata Initiative Publishes DCMI Abstract Model(''Cover Pages'', March 2005)
Dublin Core Generator A JavaScript/JQuery tool for working with Dublin core metadata code
{{Authority control
Archival science
Bibliography file formats
Information management
Interoperability
ISO standards
Knowledge representation
Library cataloging and classification
Metadata standards
Museology
Records management
Reference models
Semantic Web