Library classification invariably requires written has of damps and their subdivisions arranged in a systematic way along with corresponding symbols denoting classes. This systematic and elaborate list of classes is known as Schedules. Schedules along with an alphabetical index of classes referring to their symbols, and with some auxiliary concepts called common subdivisions, is known as Classification System. There are various systems of classification, e.g., the Dewey Decimal Classification, Ranganathan's " Colon Classification, and the Library of Congress 'Classification. There are about half a dozen living general classification systems. An index is an alphabetical approach to the systematic schedules. Topics which are scattered by discipline in the schedules are collocated in the index. In addition to the schedules which are the core of a classification' system, there are some auxiliary tables ' of some recurring concepts, say geographical isolates, time isolates; language isolates, form of presentation of the document (e.g., whether a dictionary or a cotiferenc6 proceeding) or to "physical format, say book, journal, floppy, maps, CD-ROM or 4 videotape. These recurring concepts are issued once and for. all along with their given symbol. These auxiliary concepts are known as Standard Subdivisions in the DDC; Common Isolates in the CC and Common Auxiliaries in the UDC. These usually represent the various non-subject aspect of a document or some peripheral but recurring subject aspects.
The schedules may be either in print form or in electronic form, say, on a floppy or CD-ROM. The DDC, 21st edition (1996), is available in a CD-ROM format entitled Dewey for Windows.
A designer of a classification system is known as classificationist. S.R. Ranganathan, Melvil Dewey, H.E. Bliss, C.A. Cutter are a few outstanding names of classificationists. A person who operates these systems is known as classifier. Through BLIS-03P Course you are learning to be a classifier. The majority of the librarians are; classifiers, too.