Sterling Memorial Library in the context of "Yale University Library"

A library catalog (or library catalogue in British English) is a register of all bibliographic items found in a library or group of libraries, such as a network of libraries at several locations. A catalog for a group of libraries is also called a union catalog. A bibliographic item can be any information entity (e.g., books, computer files, graphics, realia, cartographic materials, etc.) that is considered library material (e.g., a single novel in an anthology), or a group of library materials (e.g., a trilogy), or linked from the catalog (e.g., a webpage) as far as it is relevant to the catalog and to the users (patrons) of the library.

The earliest library catalogs were lists, handwritten or enscribed on clay tablets and later scrolls of parchment or paper. As codices (books with pages) replaced scrolls, so too did library catalogs become like handwritten ledgers and, in some cases, printed books. During the late 18th century through mid-19th century, cataloguing on paper slips or cards gradually replaced ledgers and books as the main medium for library catalogs, and in the 20th it was long ubiquitous. The card catalog was a familiar sight to library users for generations. Computerized cataloguing developed gradually from the mid-20th, and by the late 20th and early 21st, it had mostly replaced card catalogs. The advent of the web brought about ubiquitous use of online public access catalogs (OPACs). Some people still informally refer to the online catalog as a "card catalog".

G. Owen Bonawit (1891–1971) was an artist whose studio created thousands of pieces of stained glass for Yale, Duke, Northwestern, and Southeast Missouri State universities; Connecticut College; Bethesda By The Sea Episcopal Church in Palm Beach, Florida and at private homes. There are, by one count, 887 pieces in Yale's Sterling Memorial Library. Bonawit worked often and closely with the architect James Gamble Rogers. His career peaked around 1930; his last major commission was in 1940.