Subject cataloging depends on lists of controlled subject access vocabulary and thesauri. Library of Congress catalog records generally feature subject access points from one or more of the following thesauri and headings lists.

Library of Congress Subject HeadingsLibrary of Congress Subject Headings

Library of Congress

In publication since 1909, Library of Congress Subject Headings (LCSH) is the only subject headings list accepted as a worldwide standard. LCSH is available through Classification Web, which is updated daily; subscriptions may be purchased through the Cataloging Distribution Service. In addition, free PDF files of the current annual edition may be freely downloaded from LC’s Acquisitions and Bibliographic Access web page. LCSH authority records may also be downloaded in a variety of formats from the LC Linked Data Service: Authorities and Vocabularies (id.loc.gov).

New headings and revisions to existing headings are approved every month. The approved monthly lists are available on the Acquisitions and Bibliographic Access web page.

Library of Congress Genre/Form Terms for Library and Archival Materials (LCGFT)

Library of Congress

Library of Congress Genre/Form Terms for Library and Archival Materials (LCGFT) provides over 600 terms that describe what something is instead of what it is about. As of late 2014 it includes terms in the disciplines of moving images (films and television programs), sound recordings, cartography, and law. Projects to add terms for literature, music, religion, and “general” terms (e.g., dictionaries, encyclopedias) are underway.

LCGFT is available through Classification Web, which is updated daily; subscriptions may be purchased through the Cataloging Distribution Service.  In addition, free PDF files of the current annual edition may be freely downloaded from LC’s Acquisitions and Bibliographic Access web page. LCGFT authority records may also be downloaded in a variety of formats from the LC Linked Data Service: Authorities and Vocabularies.

New terms and revisions to existing terms are approved every month.  The approved monthly lists are available on the Acquisitions and Bibliographic Access web page.  Further information on the projects may be found on the Library of Congress’ genre/form projects web page.

Library of Congress Medium of Performance Thesaurus for Music (LCMPT)

Library of Congress

First released in 2014, the Library of Congress Medium of Performance Thesaurus for Music (LCMPT) is a tool for describing the instruments, voices, etc., used in the performance of musical works. 

LCMPT is available through Classification Web, which is updated daily; subscriptions may be purchased through the Cataloging Distribution Service.  Full MARC 21 authority records in MARC UTF-8 format may be freely downloaded from Classification Web. LCMPT authority records may also be downloaded in a variety of other formats from the LC Linked Data Service: Authorities and Vocabularies (id.loc.gov)

New terms and revisions to existing terms are approved every month.  The approved monthly lists are available on the Acquisitions and Bibliographic Access web page.

Ethnographic Thesaurus (AFSET)

American Folklife Center (Library of Congress) and the American Folklore Society

The AFS (American Folklore Society) Ethnographic Thesaurus (AFSET) is an online vocabulary for providing access to and indexing materials in folklore, ethnomusicology, ethnology, and related fields. The thesaurus includes more than 16,000 terms and was developed by the American Folklore Society in cooperation with the American Folklife Center at the Library. New terms are added regularly. 
Go to the AFS Ethnographic Thesaurus

Thesaurus for Graphic Materials (TGM): Subject and Genre Terms

Prints and Photographs Division (Library of Congress)

The Thesaurus for Graphic Materials (TGM) is a tool for indexing visual materials by subject and genre/format. The thesaurus includes more than 7,000 subject terms to index topics shown or reflected in pictures, and 650 genre/format terms to index types of photographs, prints, design drawings, ephemera and other categories. New terms are added regularly.  TGM is searchable through the Prints and Photographs Online Catalog (PPOC).
Go to the Thesaurus for Graphic Materials (TGM)
Go to the application guidelines for the Thesaurus for Graphic Materials (TGM)

RBMS Controlled Vocabularies: Controlled Vocabularies for Use in Rare Book and Special Collections Cataloging

Bibliographic Standards Committee of the Rare Books and Manuscripts Section (Association of College and Research Libraries/American Library Association)

These searchable thesauri provide standardized vocabulary for retrieving special collections materials by form, genre, or by various physical characteristics that are typically of interest to researchers and special collections librarians, and for relating materials to individuals or corporate bodies. They include the following vocabularies: Binding Terms; Genre Terms; Paper Terms; Printing & Publishing Evidence; Provenance Evidence; and, Type Evidence.
Go to RBMS Controlled Vocabularies

Guidelines on Subject Access to Individual Works of Fiction, Drama, Etc. (GSAFD)

Subject Analysis Committee (American Library Association)

Guidelines on Subject Access to Individual Works of Fiction, Drama, Etc. is a list of genre and form headings applicable to works of literature and is designed to assist with the provision of readers’ advisory services.  The Library of Congress is assigning GSAFD headings to cataloging records for individual works of literature in English until LCGFT terms for literature are ready for use. 
Go to Guidelines on Subject Access to Individual Works of Fiction, Drama, Etc.

Moving Image Genre-Form Guide (MIGFG)

Compiled by Brian Taves, Judi Hoffman, Karen Lund
Motion Picture, Broadcasting & Recorded Sound Division (Library of Congress)

The Moving Image Genre-Form Guide is a thesaurus of genre/form terms applicable to the moving image holdings of archives and libraries.  MIGFG terms ceased to be used in new cataloging records produced by the Library of Congress in 2009 when LCGFT was implemented, but the terms may still be found in older cataloging. 
Go to the Moving Image Genre-Form Guide

Radio Form/Genre Terms Guide (RADFG)

Motion Picture, Broadcasting & Recorded Sound Division (Library of Congress)

The Radio Form/Genre Terms Guide is a thesaurus of genre/form terms applicable to library and archival holdings of radio programs. RADFG terms ceased to be used in new cataloging records produced by the Library of Congress in 2009 when LCGFT was implemented, but the terms may still be found in older cataloging. 
Go to the Radio Form/Genre Terms Guide

CRS Legislative Subject Terms

Congressional Research Service

The CRS Legislative Subject Terms is a set of over 500 subject indexing terms for use with the THOMAS Bill Summary & Status Databases beginning with the 111th Congress. Terms assigned to legislation from the 110th and earlier Congresses came from a list that was based upon a thesaurus known as the Legislative Indexing Vocabulary (LIV).  CRS plans to convert the LIV terms assigned to bills from the 93rd through the 110th Congresses to the new Subject terms as time and resources permit. 
Go to the CRS Legislative Subject Terms