This document supersedes the most recent editions of the USMARC Format for Bibliographic Data and the Canadian MARC Communication Format for Bibliographic Data.  With alignment of these formats in 1997, a single edition of the format could be issued.

USMARC Documentation:

MARC 21 supersedes the 1994 edition of USMARC Format for Bibliographic Data:  Including Guidelines for Content Designation and updates No. 1 (March 1995), No. 2 (March 1996), and No. 3 (July 1997) to that edition.  With Update No. 3, the USMARC and CAN/MARC formats were identical format specifications.  The 1994 edition superseded the 1988 edition of the format and its four updates published between 1988 and 1991.  The 1988 edition incorporated the base text of the 1980 edition published under the title MARC Formats for Bibliographic Data (MFBD) and the 15 updates to that edition published between 1980 and 1987.  The 1980 edition was a compilation of separate MARC format documents developed for different types of material and published between 1969 and 1977.

CAN/MARC Documentation:

MARC 21 supersedes the 1994 edition of Canadian MARC Communication Format for Bibliographic Data and its six updates published between 1994 and 1998.  Update number six contained the changes to CAN/MARC required to align with USMARC.  With this update, the specifications contained in the CAN/MARC and USMARC formats were identical.  The 1994 edition superseded the 1988 edition and its seven updates issued between 1988 and 1991.  The 1988 edition was produced by amalgamating separately issued CAN/MARC formats for monographs and serials.

See also:

Bibliographic Data Format:  Introduction