The Machine-Readable Cataloging (MARC) standards are made up of the MARC formats, which are standards for communicating and representing bibliographic and other related information in machine-readable form. The Machine-Readable Cataloging also defines a bibliographic format for data which was developed at the Library of Congress in the 1960s by Henriette Avram. MARC provides the protocol through which there can be exchange and interpretation of bibliographic information by various computers. A lot of library catalogs in use today have their foundation in the data elements in MARC are the foundation of most.
The current record structure of MARC is an implementation of ISO 2709, also known as ANSI/NISO Z39.2. "MARC records are composed of three elements: the record structure, the content designation, and the data content of the record. The record structure implements national and international standards (e.g., Z39.2, ISO2709). The content designation is "the codes and conventions established to identify explicitly and characterize data elements within a record and support their manipulation. The content of data elements in MARC records is defined by standards outside the formats." (Evans, G.E. 1995)
The future and projected future status of the MARC record formats has been a topic for debate in the library science community throughout the world. Although the storage formats for MARC are based on a somewhat outdated technology, and the format is quite complex, there really is no alternative bibliographic format that has the same degree of granularity as the MARC. Due to the large user base with billions of records in tens of thousands of various libraries it might have the problem of inertia. Over the past 40 years, the MARC record has evolved considerably to reach its current status as MARC21. Over roughly the same period, the Anglo-American Cataloguing Rules have evolved in parallel, as have, over a shorter period, the ISBDs. However, there will be no AACR3 - AACR2's place will be taken by Rules for Description and Access (RDA), based on the principles set out in Functional Requirements for Bibliographic Records (FRBR). There has also been considerable discussion of the continued relevance of the MARC format, the best-known example of which is probably Tennant (2000), and RDA has been criticized by Gorman (2007). FRBR, devised by IFLA, is explained by Tillett (2004). In order to facilitate the usage of machine-readable cataloging (MARC) data, there must be committed record format and data element standardization. Several research libraries have initiated early machine readable formats in order to attend to the requirements of the systems in various libraries. In the development of machine-readable cataloging, experience can be drawn from other libraries for the establishment of a standard that will be acceptable to the research library community, and which will be used for interchanging bibliographic data.
By the mid 1960S, computers were being used for the production of machine readable catalog records by the Library of Congress. "Between1965 and 1968, LOC began the MARC I project, followed quickly by MARC II. MARC