MARC standards

MARC is an acronym for MAchine-Readable Cataloging. It is a 'communications standard [for] exchanging bibliographic, holdings, and other data'(2) between libraries. It defines a bibliographic data format that emerged from a United States Library of Congress-led initiative that began in the 1970s. It provides the protocol by which computers exchange, use, and interpret bibliographic information. Its data elements make up the foundation of most library catalogs used today.

The MARC Standards Office is part of the Library of Congress.

The record structure of MARC is an implementation of ISO 2709, also known as ANSI/NISO Z39.2.

The future of the MARC formats is a matter of some debate in the worldwide library science community. On the one hand, the formats are quite complex and are based on outdated technology. On the other, there is no alternative bibliographic format with an equivalent degree of granularity.

MARC record types
Authority records -- MARC authority records provide information about individual names, subjects, and uniform titles. An authority record establishes an authorized form of each heading, with references as appropriate from other forms of the heading.

Bibliographic records -- MARC bibliographic records describe the intellectual and physical characteristics of bibliographic resources (books, sound recordings, video recordings, and so forth).

Holdings records -- MARC holdings records provide copy-specific information on a library resource (call number, shelf location, and so forth).

MARC "flavours"
There are many national as well as international "flavours" (variants) of MARC, including


 * USMARC: national MARC of the United States, now obsolete.
 * MARC 21: the "harmonization" of USMARC and CAN/MARC
 * AUSMARC: national MARC of Australia, published by the National Library of Australia in 1973; USMARC adopted in 1991
 * BIBSYS-MARC: used by all Norwegian University Libraries, the National Library, all college libraries, and a number of research libraries.
 * CAN/MARC: national MARC of Canada, now obsolete.
 * CMARC: national MARC of the Republic of China, based on UNIMARC
 * DANMARC: national MARC of Denmark, based on MARC21
 * INTERMARC: MARC used by Bibliothèque nationale de France
 * NORMARC: national MARC of Norway, based on MARC21
 * UNIMARC: created by IFLA in 1977, it is the official MARC in France

MARC 21 is not a new format. The original American version of MARC became USMARC in the 1980s; there was also a separate Canadian version with minor differences called CAN/MARC. After making minor changes to both formats, the USMARC and CAN/MARC specifications were merged in 1997 to create MARC 21, the name intended to reflect the 21st century. The British Library has announced that it will no longer develop the UKMARC standard it had maintained since 1975, in favour of MARC 21.