Machine Readable Cataloguing (MARC): MARC format has become a generic term to all MARC formats including UKMARC, CANMARC, InterMARC, etc. which are used for the identification and arrangement of bibliographical data for handling by computer.
The first conference on Machine Readable Cataloguing was sponsored by the Library of Congress. The committee on Automation of the Association of Research Libraries (ARL) and Council of Library Resources (CLR) was met at the Library of Congress. This conference recommended that
i) MARC records should include additional information to be used as multipurpose records, in addition to information available on printed card;
ii) The element of MARC data should be standardized;
iii) MARC records should be produced and distributed to libraries which have automated system.
In the second conference held at the Library of Congress in November 1965, Library of Congress sought funds from CLR and in December 1965 it received a grant to conduct a pilot project.
In early January 1966 the planning for the pilot project began. The third conference was held in February 1966 at the Library of Congress which was considered the official opening of the pilot project for machine readable cataloguing data. The pilot project was called MARC I. In this way the MARC I format was set up in April 1966 which was restricted to books only. The distribution of regular weekly service of MARC tapes started from Nov. 1966. The MARC I format was based entirely on the structure of the Library of Congress catalogue card. So, BNB (with active collaboration with Library of Congress) made some operational changes to make it interchangeable record format. As a result, MARC II was developed. It is capable of containing bibliographic data of all forms of library material such as books, monographs, serial, map, music, etc. By subscribing to this service a library can acquire Magnetic tapes in machine readable form.
Due to the differences between the British Library and the Library of Congress MARC II was later split into two formats - BNB MARC (later UK MARC) and US MARC. The USMARC format becomes the U. S. National Standard in 1971 (ANSI Z39.2) and an International Standard in 1973 (ISO 2709). The MARC II also influenced the other countries to develop their own standard format which followed the same structure but the tags were slightly different. As a result, certain amount of incompatibility exists among the different countries. To solve this problem IFLA launched a programme known as UNIMARC, but eventually it failed.
A) Structure of MARC Tapes
a) Leader: It provides information about ensuring such records as total length of the record, the type of record, etc. It is 24 characters (00-23) long.
b) Record Directory: It shows what variable fields are in the record and what their locations in the record are. It is of 12 characters long.
c) Variable Field: The variable fields are of two types- Variable Control Field (001-009) and Variable Data Field.
B) Advantages of Using MARC:
a) MARC tapes can be used by individual libraries for producing their conventional card catalogue / book form of catalogue, etc.
b) It helps in the creation of centrally prepared catalogue.
c) Distribution of MARC tapes to the receiving libraries avoid duplication of effort.
d) Uses of MARC tapes make different library softwares compatible to one another.
e) MARC tapes can be used for computerized SDI services.
f) MARC tapes perform sharing of bibliographical information.