Reaching decisions and adjusting: RDA and OCLC
Resource Description and Access (RDA), the successor to the Anglo-American Cataloging Rules (AACR), has had a significant impact on both bibliographic and authority data as they are represented in Machine-Readable Cataloging records in MARC 21. A brief history of the develoment of RDA is outlined. Since 2006, OCLC has kept up with some fifteen MARC 21 Bibliographic, Authority, and Holdings Updates through a total of nine OCLC-MARC Updates. Many of the new fields and indexes implemented by OCLC are listed, many of them directly related to RDA. The MARC fields for Content Type (336), Media Type (337), and Carrier Type (338) are given special attention, as they collectively replace and improve upon the AACR concept of the General Material Designation (GMD). In addition to the many new indexes implemented, including the "Entity Attributes" indexes in both the Bibliographic and Authority files, newly defined elements have been added to many existing indexes. RDA-related updates have also been made to OCLC's Connexion browser and client interfaces. OCLC policies regarding RDA records are discussed, including some of the automated changes to existing records that are underway.