This article is from the Libraries FAQ, by Anthony Wilson email@example.com with numerous contributions by others.
0: Generalities. Science and Knowledge Organization. Information
Documentation. Librarianship. Institutions. Publications.
1: Philosophy and psychology
2 : Religion and theology
3 : Social sciences; Statistics; Politics; Economics; Trade; Law;
Governments; Military affairs; Welfare; Insurance; Education; Folklore
4 : [vacant]
5 : Mathematics and natural sciences
6 : Applied Sciences
7 : The Arts. Recreation. Entertainment. Sport
8 : Language. Linguistics. Literature
9 : Geography. Biography. History