Anglo-American Cataloguing Rules (AACR) were an international library cataloging standard. First published in 1967 and edited by C. Sumner Spalding,[1] a second edition (AACR2) edited by Michael Gorman and Paul W. Winkler was issued in 1978, with subsequent revisions (AACR2R) appearing in 1988 and 1998; all updates ceased in 2005.