This entry covers both the Anglo-American Cataloguing Rules of 1967 and the Anglo-American Cataloguing Rules, 2nd edition of 1978 and later. These were the most important advances in English-language codes for descriptive cataloging during the twentieth century. The 1967 code, produced in different American and British editions, included rules for choice and form of headings as well as rules for description, the former being based on the outcomes of the Paris Conference on Cataloguing Principles of 1961. The advent of International Standard Bibliographic Description (ISBD) brought changes to the rules for description, and these were incorporated in the 1978 code, which for the first time instituted a formal separation between description and access points. Significant features of both editions are described.