This standard includes data elements that are exchanged or are potentially exchanged among bibliographic systems. Those elements that are not exchanged or not likely to be exchanged are ignored as they do not need standardisation. Data elements being handled by transport protocols are not included, only those related to application level protocols.The standard was previously published in five parts as follows:Part 1: Interloan applications (1988)Part 2: Acquisitions applications (1992)Part 3 : Information retrieval applications (1994)Part 4 : Circulation Applications (1998)Part 5 : Data elements for the exchange of cataloguing data and metadata (2002)The el