LCThe Metadata Authority Description Schema (MADS) is an XML-based standard for describing authoritative entities -- the people, organizations, events, and controlled terms that appear as access points in bibliographic records. Developed by the Library of Congress as a companion to the Metadata Object Description Schema (MODS), MADS provides a way to create and exchange authority data outside the constraints of the MARC 21 format while maintaining compatibility with existing MARC authority records.
Background
MADS was developed in the mid-2000s by the Library of Congress Network Development and MARC Standards Office in response to the need for an XML-native authority format. Libraries had long maintained authority records in MARC 21 to control the forms of names, subjects, and other access points used in cataloging. As XML-based metadata formats like MODS gained traction, a parallel XML authority format was needed to complement them.
MADS was designed to carry selected data from MARC 21 authority records and to enable the creation of original authority records in XML. An RDF/OWL version, MADS/RDF, was subsequently developed to support linked data applications, with its own namespace and ontology.
Purpose and Scope
MADS provides structured descriptions of several types of authoritative entities:
- Personal names -- individuals serving as authors, contributors, or subjects
- Corporate names -- organizations, institutions, and bodies
- Name/title combinations -- an authority linking an agent to a specific work
- Titles -- uniform titles and series titles
- Topics -- subject headings and topical terms
- Geographic names -- place names used as access points
- Genres/forms -- terms describing the nature or genre of a resource
- Occupations -- terms describing vocations
Each MADS record can include variant forms, related authorities, notes, and source references. The schema supports the source code lists maintained by the Library of Congress for subject headings, name/title authorities, genre/form terms, and other categories.
Serializations and Technical Formats
MADS is available in two primary forms:
- MADS XML -- defined by an XSD schema, currently at version 2.1. Earlier versions (2.0, 1.0) remain available.
- MADS/RDF -- an OWL ontology using the namespace
http://www.loc.gov/mads/rdf/v1, suitable for linked data environments.
XSLT stylesheets are provided to convert MARCXML authority records into MADS XML (both XSLT 1.0 and 2.0 versions), and a mapping document details the correspondence between MARC authority fields and MADS elements.
Key Elements
MADS XML records center on a main authority element that identifies the type (personal, corporate, topic, etc.) and its authorized form. Supporting elements include:
| Element | Purpose |
|---|---|
mads:authority |
The authorized (preferred) form of the heading |
mads:variant |
Variant (non-preferred) forms |
mads:related |
Related authorities |
mads:affiliation |
Organizational affiliation of a person |
mads:note |
Scope notes, source notes, biographical notes |
mads:url |
Associated URL |
mads:identifier |
Control numbers and other identifiers |
mads:extension |
Container for additional metadata from other schemas |
Governance and Maintenance
MADS is maintained by the MODS/MADS Editorial Committee in collaboration with the Network Development and MARC Standards Office at the Library of Congress. Community input is gathered through the shared MODS listserv, which covers both MODS and MADS. Changes between schema versions are documented in formal change lists published on the official site.
Notable Implementations
MADS is used primarily in the library and cultural heritage sectors:
- The Library of Congress uses MADS in conjunction with MODS for its digital collections
- Institutions using MODS-based cataloging workflows often pair MADS for authority control
- The MADS Implementation Registry on the LOC site lists adopting institutions
- Library systems that support MODS typically also handle MADS authority records
- MADS/RDF is used in linked data projects that expose library authority data as RDF
Related Standards
- MODS (Metadata Object Description Schema) -- MADS is designed as its authority companion
- MARC 21 Authority Format -- MADS can carry data from MARC authority records
- MARCXML -- the XML serialization of MARC, with conversion stylesheets to MADS
- SKOS -- an alternative W3C vocabulary for representing authority-like concept schemes in RDF