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Metadata Standards by Community

Seeing Standards: A Visualization of the Metadata Universe is a good illustration of the complexity of choice we have when deciding which metadata standards to implement.

The standards listed below are typically implemented by libraries or other metadata experts. For consulations with these or other metadata standards, please contact us, at

Archives and Special Collections

Describing Archives: A Content Standard (DACS; available online through SAA) “…an output-neutral set of rules for describing archives, personal papers, and manuscript collections [that] can be applied to all material types. It is the US implementation of international standards (i.e., ISAD(G) and ISAAR(CPF)) for the description of archival materials and their creators.” – Society of American Archivists

Encoded Archival Description (EAD) is a mark-up language for archival finding aids, that is, detailed descriptions of collections that contain a wide variety of materials, including letters, diaries, photographs, drawings, printed material, and objects.

Art and Visual Resources

Cataloging Cultural Objects: A Guide to Describing Cultural Works and Their Images (CCO; available online) “…a manual for describing, documenting, and cataloging cultural works and their visual surrogates. The primary focus of CCO is art and architecture, including but not limited to paintings, sculpture, prints, manuscripts, photographs, built works, installations, and other visual media. CCO also covers many other types of cultural works, including archaeological sites, artifacts, and functional objects from the realm of material culture.”—CCO Commons

Categories for the Description of Works of Art (CDWA) is a conceptual framework for describing and accessing information about works of art, architecture, other material culture, groups and collections of works, and related images.

Getty Art and Architecture Thesauri (AAT) is a structured vocabulary for terms used to describe art, architecture, decorative arts, material culture, and archival materials.

Getty Union List of Artist Names (ULAN) is a structured vocabulary for names and other information about artists.

MIX is an XML schema for recording and exchanging image technical metadata defined by NISO Z39.87 Data Dictionary –Technical Metadata for Digital Still Images (see below).

NISO Z39.87 defines a data dictionary, that is, a set of formal properties with specific semantics, applicable for the detailed technical description of digital raster still images. These properties were selected with particular attention to their significance for preservation assessment and manipulation. LDI staff were involved in writing the original draft version of the standard and in the subsequent development of the standard in its final form, as well as in the follow-on activity to create MIX, an XML schema for expressing Z39.87 metadata in a standard form. The metadata stored in the Digital Repository Service (DRS) for images is consistent with the Z39.87 standard.

Thesaurus of Graphic Materials I: Subject Terms (TGM-I) consists of terms and numerous cross references for the purpose of indexing topics shown or reflected in pictures.

Thesaurus of Graphic Materials II (TGM-II) is a thesaurus of terms to describe Genre and Physical Characteristic Terms.

VRA Core 4.0 A metadata element set providing a categorical organization for the description of works of visual culture as well as the images that document them.


Darwin Core “…a standard designed to facilitate the exchange of information about the geographic occurrence of species and the existence of specimens in collections.”—Darwin Core wiki.


Data Documentation Initiative “An international XML-based standard for the content, presentation, transport, and preservation of documentation for datasets in the social and behavioral sciences…”

Ecological Metadata Language A specification and set of XML schemas designed to document ecological datasets.


Anglo-American Cataloguing Rules, 2nd Ed. Rev. (AACR2) The primary set of rules used by libraries to create catalogs and other lists. The rules cover the description of, and the provision of access points for, commonly collected library materials.

Dublin Core A set of metadata terms defined to support resource description and discovery across domains. A subset of the terms, the Dublin Core Metadata Element Set (NISO Z39.85), consists of the original fifteen elements used without any qualification. This set of terms is also referred to as Simple Dublin Core and is a required format in the Open Archives Initiative.

Getty Thesaurus of Geographic Names (TGN) is a structured vocabulary for names and other information about places.

Library of Congress Subject Headings (LCSH) comprises a thesaurus of subject headings, maintained by the United States Library of Congress.

Library of Congress Name Authorities (LCNA) includes Corporate Names, Geographic Names, Conference Names, Personal Names.

MARC21 is the primary library standard for the representation and communication of bibliographic and related information in machine-readable form. MARC21 is an implementation of ANSI/NISO Z39.2, Information Interchange Format. It is used at Harvard to communicate resource descriptions between the HOLLIS system and external systems and services.

MARCXML is one standard way of representing MARC21 metadata in XML. The schema is very compact. Rather than defining elements for each MARC field, the schema defines field and subfield types, and the specific tags, indicators and subfields are supplied as uncontrolled attribute values. This design decision makes the MARCXML schema suitable for communication but not for validation of MARC metadata.

MODS An XML schema of a simple set of elements for bibliographic description, MODS was designed both to carry selected information transferred from MARC21 records and to support the creation of original resource description records. Metadata from several other domains also fit nicely into MODS, so it can be used as a common mapping format across diverse sets of metadata created according to other standards.

Resource Description and Access Intended to succeed AACR2 as “a set of guidelines and instructions on formulating descriptive data and access point control data to support resource discovery,” RDA is still under development and is scheduled to be published early in 2009. Drafts of portions of the document are available on the web site.


TEI The Text Encoding Initiative (TEI) is a consortium which collectively develops and maintains a standard for the representation of texts in digital form. Its chief deliverable is a set of Guidelines which specify encoding methods for machine-readable texts, chiefly in the humanities, social sciences and linguistics. Since 1994, the TEI Guidelines have been widely used by libraries, museums, publishers, and individual scholars to present texts for online research, teaching, and preservation.