Standards & Tools
Descriptive Metadata Schema
A metadata schema is a standardized structure for metadata which allows repositories or machines to share data with mutual understanding. The metadata schema defines the data elements (fields) or tags (labels) used to enable indexing, retrieval, display, and sharing of records by computer systems.
Note: Many of the schema listed below are proposals and have not been implemented at all or may not have been widely implemented. When in doubt, contact the authoring organization for more information.
Dublin Core. Dublin Core Metadata Terms. Dublin Core Metadata Initiative.
A set of fifteen elements (title, creator, subject, etc.), with optional qualifiers, used to structure descriptive records and facilitate information sharing. Originally intended for use in describing Web-based resources, it is now used also for describing physical collections in museums, libraries, archives, and other repositories. Approved by ANSI, the Dublin Core metadata standard is designed for simplicity of creation and maintenance, and extensibility. It uses commonly understood terminology and is international in scope. Developed in the mid-1990s.
EAD. Encoded Archival Description.
A data interchange standard for encoding archival finding aids using the Standard Generalized Markup Language (SGML). Defines the structural elements (and their interrelationships) to be used in creating archival inventories or registers (finding aids that supplement broad collection descriptions for archival collections). Maintained by the Library of Congress in partnership with the Society of American Archivists.
IEEE-LOM. Institute of Electrical and Electronics Engineers - Learning Object Metadata.
A set of elements used to structure descriptive records and facilitate information sharing. Intended for use in describing learning objects, online learning or instructional materials which have been created by a variety of software such as presentation software or complex authoring software. Developed in the late 1990s.
Standard providing a general framework for the description of different kinds of library materials (books, serials, electronic resources, etc.), including the order of elements in the catalog entry and prescribed punctuation. ISBDs have been integrated into several catalog codes around the world, including AACR2 and AMIM.
MARC. MAchine Readable Cataloging Formats. Washington, D.C.: Library of Congress.
A series of detailed standards for the structuring or tagging of data to facilitate the interchange of records between databases or files. The principal format is the MARC 21 Format for Bibliographic Data, used for descriptions of library and archival materials. There are also formats for Authority (for controlled vocabularies, or established lists of preferred terms with cross references), Holdings, Classification, and Community information, and a variety of code lists for use with the standard. Developed in the 1960s.
The MARC Web site includes introductory information on MARC, documentation of all MARC formats, code lists, crosswalks, MARC in XML, and more, in English and Spanish.
The Formats exist in full and concise versions. Concise versions, as well as the code lists, are available online:
MARC 21 Concise Authority Format
MARC 21 Concise Bibliographic Format
MARC 21 Concise Classification Format
MARC 21 Concise Community Information Format
MARC 21 Concise Holdings Format
MARC Code List for Geographic Areas
MARC Code Lists for Organizations
MARC Code Lists for Relators, Sources, and Descriptive Conventions
A standard set of elements or labels to structure descriptive records. Intended to be able to carry selected data from existing MARC 21 records as well as to enable the creation of original descriptive records. It includes a subset of MARC 21 bibliographic fields and uses language-based tags rather than numeric ones, in some cases regrouping elements from the MARC 21 bibliographic format. Expressed using the XML schema language of the World Wide Web Consortium. May be used for a variety of purposes, and particularly for library applications.
MPEG-7. Multimedia Content Description Interface, or ISO 15938. Moving Picture Experts Group.
An international standard for description of multimedia resources, including still images, moving images, audio, etc. Uses XML for the textual representation of content, supports descriptions at the segment level (i.e., shots or clips), supports textual and non-textual data, and can marry both in indexing. Can reside native on an MPEG-4 stream. Primarily used for born-digital materials. Originally released in late 2001.
PBCore. Public Broadcasting Metadata Dictionary.
Designed to provide a standard way of describing and using metadata for public broadcasters and associated communities. PBCore is built on the foundation of the Dublin Core and has been reviewed by the Dublin Core Metadata Initiative Usage Board.
SMEF. Standard Media Exchange Framework, British Broadcasting Corporation.
A data dictionary which defines the attributes of data, the entities into which the data is grouped, and the relationships between these entities. It attempts to include all data a business needs to know about a particular media item throughout its life-cycle.
Metadata schema for digital audiovisual materials, designed for the production environment and covering the entire production chain: pre-production, post-production, acquisition, distribution, broadcasting, storage and archiving.
VRA Core. VRA Core Categories, Version 3.0. Visual Resources Association Data Standards Committee.
A standard set of about 17 elements, with optional qualifiers, used to structure descriptive records and facilitate information sharing. Intended for use in describing "works of visual culture" as well as the images that document them. It follows the “1:1 principle,” developed by the Dublin Core community.