A library catalogue consists of various entries prepared for the documents acquired for the library. There are two types of entries in the library catalogue. These consist of main entry and added entries. Main entries give detailed information about the documents in various sections or areas of main entry. Added entries are prepared under various access points such as author, title, subject and usually certain brief information of the document. Thus, cataloguing is the process of making entries for a catalogue.
Following operations are to be carried out for making entries:
1) Choice and rendering of headings of main entries, added entries and sections of main as well as added entries.
2) Recording of information in the sections of entries.
3) Determination of style of writing, punctuation marks, capitalisation, etc.
4) Preparation of entries.
5) Writing call numbers on all the entries.
6) Filing of catalogue cards.
7) Preparation of guide cards.
8) Maintenance and updating of entries in a catalogue.
All these processes and procedures are included in cataloguing.
In simple terms, cataloguing is the art of preparing records in such a way that a document is quickly identified and located by the reader. Only after identification and location of a document the reader will be in a position to examine it as to its suitability for their purpose. Certainly, the catalogue provides information pertaining to the title, sub-title, contents and the series of a document. These details help the reader in determining its suitability for a particular need, which they have in mind.
Cataloguing is a practical art and is learnt by practice alone. Over the years, codes describing the rules enlisting the ways and means by which library catalogues are constructed, have been evolved. The history relating to the evolution of cataloguing codes forms a fascinating study. The Anglo-American Code of 1908, American Library Association (ALA) Codes of 1941 and 1949, the Classified Catalogue Code of S. R. Ranganathan, the Anglo-American Cataloguing Rules (AACR) edition 1 and 2 are some of the widely known cataloguing codes. The codes provide guiding principles for the preparation of entries required for the construction of a library catalogue. Reference to the rules contained in these codes leads to consistency and accuracy in the production and maintenance of library catalogues. Standardisation can be achieved by following a catalogue code. Standardisation facilitates exchange of catalogue entries amongst various libraries. Compatibility is one of the important aspects in the context of application of computers for library activities and establishment of resource sharing networks. All cataloguing codes except the Classified Catalogue Code (CCC) of Ranganathan provide rules for the preparation of author and title catalogue with additional rules for descriptive cataloguing. CCC is the only cataloguing code that provides rules for subject entries, in addition to rules relating to the choice and rendering of bibliographical items for descriptive cataloguing. Libraries that do not use CCC for cataloguing usually provide subject approaches using standard subject headings list such as Library of Congress Subject Headings or Sears List of Subject Headings.