INTERNATIONAL ACCESS TO BIBLIOGRAPHIC DATA: MARC AND MARC-RELATED ACTIVITIES ALAN HOPKINSON British Library Bibliographic Services Division Formats for the exchange of bibliographic data use the ISO 2709 record structure which started out as the structure for the Library of Congress MARC format. The UNISIST Reference Manual was an early international exchange format developed by ICSU-AB and Unesco and included cataloguing rules suitable for use by A & I Services. The national libraries developed UNIMARC under IFLA auspices as their exchange format since the national formats were not totally compatible. Unesco, concerned about the lack of compatibility between the major interna- tional exchange formats, sponsored a symposium, resulting from which a Com- mon Communication Format was developed and ISO began work on a data ele- ment directory. International formats also exist for nuclear and agricultural infor- mation as well as for serials data. Other formats exist which are used internation- ally and have different structural characteristics. The International MARC Net- work Study Steering Committee has taken an interest in the exchange of bibliographic data and has organized a test of UNIMARC and supervised a UNIMARC Handbook to clarify the format. International exchange formats tend to acquire accompanying cataloguing rules: indeed they will only be really effec- tive if there are internationally accepted cataloguing rules and authority files. 1. INTRODUCTION THE PRECEDING PAPER by Anthony Long (Journal of Documentation, 40(1), March 1984, 1-12) shows how MARC began as an Anglo-American develop- ment and then spread world-wide. The main thrust behind MARC came from the Library of Congress and the feature which all the different national MARC for- mats had was their record structure, a record structure based on the international standard ISO 2709. In practice national formats have probably based their record structure directly on the Library of Congress MARC format. Within the United States, the record structure, but not the data element definitions nor the content designators identifying them became a national standard in 1971. 1 Three systems of content designators were included in the first edition as an appendix but not in the subsequent version in 1979. 2 The record structure alone was given the status of an international standard in 1973 as ISO 2709. 3 A common record structure was adopted to enable organizations to exchange records on magnetic tape. This structure reflects the state of the art in data processing at the time it was for- mulated; magnetic tape was an important storage medium since disk storage was expensive. The ISO 2709 structure consists of a leader or label containing data needed to process the records. For example, one code indicates the type of record, whether it relates to a book, serial, cartographic material etc., and another in- dicates the bibliographic level, analytic, monograph, serial or collection. Some systems which process records in ISO 2709 format depend on these codes to pull in the appropriate computer programs for processing. The leader is followed by a directory which identifies the types of data in the record and points to the posi- Journal of Documentation, Vol. 40, No. 1, March 1984, pp. 13-24. 13