The union card catalog in the nave of Sterling Memorial Library contains 11,986 drawers, representing over 100 years of cataloging records for the fourth largest library in the United States. It contains cards for material in most, but not all, formats held by most, but not all, libraries in the Yale University Library system represented on a combination of handwritten, half-height cards; typewritten cards; and computer-produced cards.
The current catalog represents the final evolutionary state of a living document that has changed over time as the content of catalog records, their format, and their arrangement have evolved under many codes of cataloging rules.
The catalog is best approached, not merely as a location tool, but as a complex bibliographic tool that happens to exist in card format. The principles under which records for this catalog were created and arranged have importance beyond merely this catalog and are identical to those governing the organization and arrangement of many printed bibliographies whose headings and form of entry -- unlike those in card or electronic catalogs -- will never change.
With full catalog records, that is, records offering all modern points of access (author, title, subject, editor, illustrator, translator, etc.) appearing in Orbis only for material cataloged since 1977 and for other discrete groups of records which have been converted to electronic form, the card catalog remains the fullest -- yet still incomplete -- record of Yale's library collections.