The Dewey Decimal Classification (DDC), or Dewey Decimal System, is a proprietary library classification system created by Melvil Dewey in 1876. It has been revised and expanded through 23 major editions, the latest issued in 2011. Dewey was responsible for all revisions until his death in 1931. A designation number, such as Dewey 16 for the 16th edition, is given for each revision. Read more at Wikipedia...

000 GENERALITIES
000 Computer Science, knowledge & systems
010 Bibliographies
020 Library & information sciences
030 Encyclopedias & books of facts
060 Associations, organizations & museums
070 News media, journalism, publishing
080 General collections (e.g. quotations)

100 PHILOSOPHY & PSYCHOLOGY
100 Philosophy
110 Metaphysics (the study of the fundamental nature of being and the world)
120 Epistemology (the study of knowledge and justified belief)
130 Parapsychology & occultism (the study of mental phenomena & the supernatural)
140 Philosophical schools of thought
150 Psychology
160 Logic
170 Ethics
180 Ancient, medieval & eastern philosophy
190 Modern western philosophy

200 RELIGION
200 Religion (general)
210 Philosophy & theory of religion
220 The Bible
230 Christianity and Christian theology
240 Christian practice & observance
250 Christian pastoral practice & religious orders
260 Christian organization, social work & worship
270 History of Christianity
280 Christian denominations
290 Other religions

300 SOCIAL SCIENCES
300 Sociology and anthropology
310 Statistics
320 Political science
330 Economics
340 Law
350 Public administration & military science
360 Social problems & social services
370 Education
380 Commerce, communications & transportation
390 Customs, etiquette & folklore

400 LANGUAGE
400 Language (general)
410 Linguistics
420 English & Old English languages
430 German & related languages
440 French & related languages
450 Italian, Romanian & related languages
460 Spanish & Portuguese languages
470 Latin & Italic languages
480 Classical & modern Greek languages
490 Other languages