Shared cataloging (also called collaborative cataloging) refers to groups within one organization or multiple organizations sharing access to bibliographic records of various library materials to prevent duplication of work for each individual library. Often, these individual organizations are members of a library consortium.
Before machine-based systems, the sharing of catalogs was rare. The development of computerized catalogs and MARC records increased the use of collaborative cataloging. Then, once the Internet expanded into library systems, the sharing of catalogs greatly expanded.