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About searching the Library of Congress authority file interactively

Find an overview of how to search the Library of Congress authority file in Connexion client.

Why search for authority records?

  • When creating or modifying a bibliographic record, determine the correct forms for names of persons, organizations, conferences, and/or titles associated with the resource you are describing.
  • When adding subject headings to a bibliographic record, determine established headings.

About the Library of Congress (LC) authority file

  • The Library of Congress and NACO libraries create and maintain the authority records.
  • Records are stored and displayed in the MARC authorities format.

Open authority history records

If you want to track the history or identify past changes for distributed authority records, you can open authority history record(s) from a displayed authority record using Authorities > Show > LC Superseded Versions. You can also search or browse the authority history file—for example, to check for headings you can no longer find in the LC authority file—using Authorities > Search > LC Names and Subjects History or Authorities > Browse > LC Names and Subjects History.

Authority history records are read-only. You can copy and paste or print only. Authority history file records date back to the mid-1980s.

See Open LC authority history records interactively for details.

Authority file indexes

About LC authority file indexing

  • Browsing and keyword searching use the same indexes (same fields and subfields are indexed for both), except for numeric indexes, which are unavailable for browsing.
  • Indexing differs for derived searching.
  • How you specify an index varies with the search or browse method you use:
    • When you search or browse using the Command Line Search box in the Search LC Names and Subjects dialog, you must type the index label.
    • When you use the Keyword/Numeric Search boxes of the Search window or when you use the Browse LC Names and Subjects window, do not type the index label. Instead, select the index from the list provided.
  • Numeric and derived indexes are unavailable for browsing.

List of LC authority file indexes

See Authorities: Format and indexes for comprehensive information about the format of OCLC authority records and search indexes.