Access to commonly used controlled vocabularies and other lists from the Library of Congress (LC); Examples include the Thesaurus for Graphic Materials as well as LC Subject Headings, LC Genre/Form Terms, and the Name Authority file.
LC policy decisions from meetings on subject/classification are posted weekly along with summaries; you can request to attend virtual editorial meetings
Getty Research Institute vocabularies for art, architecture, and cultural objects, including Art & Architecture Thesaurus (AAT), Cultural Objects Name Authorities (CONA), and Union List of Artists' Names (ULAN)
Headings in the Subject LC authority file with a set of subdivisions appropriate for use with other headings belonging to the category, such as religion and the arts.
Best practices for implementers wishing to apply LC faceted vocabularies--using purpose-built fields in the MARC 21 bibliographic format--retrospectively to library catalogs