Library of Congress Subject Headings: A Post-Coordinated Future

This paper is the result of a request from Library of Congress leadership to assess pre-coordinated versus post-coordinated subject cataloging. It argues that the disadvantages of pre-coordinated subject strings are perennial and continue to hinder progress, while the advantages of post-coordinated subject cataloging have expanded, resulting in new opportunities to serve the needs of catalogers and end users alike. The consequences of retaining pre-coordinated headings will have long-term impacts that heavily out-weigh the short-term challenges of transitioning to new cataloging practices. By implementing post-coordinated, faceted vocabularies, the Library of Congress will be investing in the future of libraries.