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

Washington, DC: Library of Congress

Now in its 32nd edition, Library of Congress Subject Headings is the only subject headings list accepted as the worldwide standard. The print volumes and online version (through Classification Web) are available for purchase through the Cataloging Distribution Service (CDS).

Subject headings created each week since the most recent full edition are available on the Library's Cataloging and Acquisitions Web site. A selection of new subject headings of current interest, as well as a list of revised subject headings, is published each quarter in Cataloging Service Bulletin, which is available as a free PDF download from the Cataloging Distribution Service.

NEW SERVICE (Library of Congress Linked Data Service) - Library of Congress Subject Headings is also available for download through the Library's new Linked Data Service: Authorities and Vocabularies (

Legislative Indexing Vocabulary (LIV)

Washington, DC: Congressional Research Service

The Legislative Indexing Vocabulary (LIV) is a set of approximately 5,000 subject indexing terms for use with the THOMAS Bill Summary & Status Databases prior to the 111th Congress. Go to the Legislative Indexing Vocabulary

Moving Image Genre-Form Guide

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

The Moving Image Genre-Form Guide is a thesaurus of subject terms applicable to the moving image holdings of archives and libraries. Go to the Moving Image Genre-Form Guide

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. Includes the following vocabularies: Binding Terms; Genre Terms; Paper Terms; Printing & Publishing Evidence; Provenance Evidence; and, Type Evidence. Go to RBMS Controlled Vocabularies

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

Washington, DC: 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)