The Motion Picture Copyright Descriptions Collection, Class L, consists of forms, abstracts, plot summaries, dialogue and continuity scripts, press kits, publicity and other material, submitted for the purpose of enabling descriptive cataloging for motion picture photoplays registered with the United States Copyright Office under Class L from 1912-1977.

The Motion Picture Copyright Descriptions Collection, Class M, consists of forms, abstracts, plot summaries, dialogue and continuity scripts, press kits, publicity and other material, submitted for the purpose of enabling descriptive cataloging for motion pictures other than photoplays registered with the United States Copyright Office under Class M from 1912-1977.