Discusses the need to impose a rigidly controlled structure on the machine-readable catalog, the machine capabilities and limitations for achieving that control, possibilities for machine control of the catalog, and the extension of those possibilities to permit a degree of control not possible in a manual system. (Author/LS)

Explores nature and magnitude of extensions needed in order to use a library circulation control system as an online catalog, noting Margaret Mann's eight functions of a library catalog, authority control, cross references, correlating subjects, structure revision, adding access, terminal needs, and system reliability. Nine references are cited.…