The Universal MARC format (UNIMARC) is a widely used international standard for the representation and exchange of data in machine-readable form. It covers four metadata schemas for bibliographic, classification, authorities and holdings information.
The primary purpose of UNIMARC is to facilitate the international exchange of data in machine-readable form between national bibliographic agencies. The UNIMARC is maintained by the UNIMARC Committee.
For a brief overview of the history, aims and general structure of UNIMARC, see: UNIMARC: an introduction — Understanding the UNIMARC format.