systems for the orderly arrangement of published works (and certain documentary materials) by class, subclass, and more detailed subdivisions in a logical sequence and correlation on the basis of such features as content, form of publication, and readership. In terms of content, library classifications may be either general or special-purpose.
Library-bibliographical classifications form the basis of the structure of classified catalogs (entries grouped by subject) and bibliographical card files. The classification systems are used for arranging book holdings in libraries and various types of documentary materials in information agencies. They are also used for grouping material in bibliographic manuals, for systematizing information in dictionaries and reference works compiled in accordance with the classification systems, and for gathering statistics in library and bibliographical institutions. In the USSR and abroad, centralized classification has been widely adopted, that is, classification designations, or numbers, are printed in publications.
Prior to the late 19th century enumerative classification systems, whose subdivisions were ranked in simple sequence in a single hierarchical series, were devised. The best known of these are the Dewey Decimal System (1876) and the US Library of Congress Classification (1904). With the appearance of the method of arranging by type (according to which standardized subdivisions reflecting the form of publication or geographical, chronological, or other features were created outside the main classification table) the enumerative systems were replaced by combination systems that made possible inclusion of several classification characteristics in the number. The most consistent library-bibliographical classification of this type is the Universal Decimal Classification (UDC).
Further development of the theory and practice of library-bibliographical classifications made possible the creation of analytic-synthetic, or multi-aspect, classifications. The theory of their construction was worked out by the Indian scholar and librarian S. R. Ranganathan (Colon Classification, 1933). In multi-aspect classifications there are no predetermined numbers; the classification scheme provides only the main subdivisions and is supplemented by many different tables worked out for each branch of knowledge in accordance with the categories (objects, processes) that are characteristic of the field. By adding the numbers of the category tables to the basic subdivisions, it is possible to obtain designations for the most complex concepts. The composition of the categories and their sequence in each branch of knowledge are regulated by the multi-aspect formula.
In Russia one of the first library-bibliographical classification systems was devised by the librarian A. I. Bogdanov in the mid-18th century. In the 19th century a significant contribution to the development of the theory and practice of classification systems was made by the historian A. N. Olenin, who worked out a classification scheme for the St. Petersburg Public Library; by the chemistry professor F. F. Reiss, whose classification system was designed for the Moscow University Library; and by academician K. M. Ber, who created a classification system for the Academy of Sciences Library. The prerevolutionary Russian library-bibliographical classifications were of the enumerative type.
Prior to 1927 most libraries in the USSR used different versions of the Dewey Decimal System and the Universal Decimal Classification. These tables did not contain subdivisions that took into account the phenomena of Soviet reality. A fundamental revision of the tables for Soviet libraries was carried out over many years under the leadership of L. N. Tropovskii and Z. N. Ambartsumian. The Tables of Library Classification were published in different versions for public, rural, children’s, and oblast libraries, and they were translated and published in the Union republics and in some of the socialist countries. At the same time, the Soviet combination system, the Library-Bibliographical Classification, was being developed, designed for scientific libraries (its publication was completed in 1968). By a decree of the USSR Council of Ministers (1962) the Universal Decimal Classification was adopted by technical, medical, and agricultural libraries and by scientific and technical information agencies.
E. R. SUKIASIAN