Library classification systems
Up to the 19th century, many libraries simply arranged their books by size and date of acquisition. Individual books could be found through a catalogue. Others used simple classifications. Increasing public access and size led to the introduction of various more sophisticated library classification systems, of which some important or distinctive ones are briefly covered below.
Decimal classification (1st edition, Melvil Dewey, 1876; 23rd edition, 4 volumes, Online Computer Library Center, 2011)
This system is distinctive in its use of numerals for top-level classes, as most use letters. These are as follows:
- 100 Philosophy and psychology
- 200 Religion
- 300 Social sciences
- 400 Language
- 500 Pure science
- 600 Technology
- 700 Arts and recreation
- 800 Literature
- 900 History and geography
Further subdivisions are made by adding digits in place of zeros: 510 mathematics, 423 English dictionaries etc. Beyond this, decimal points are used: 794.1 chess etc. Books of a more general nature are not so subdivided, but have their own subdivisions: 033 German encyclopaedias, 501 philosophy of science etc.
This system is used in most libraries in the English-speaking world. Note, however, that it is used, not followed. In particular, it is usually ignored for fiction, which it would distribute among various national literatures: 813 American fiction, 823 British fiction etc. Most libraries put all fiction in English (including translations from other languages) in alphabetical sequence outside the classification.
TBC