Guide cards
The 65 divisions
These are the four-digit numbers, and the only place taxonomy lives in the whole system. Cut a tab for each; everything else files behind one of them at an address that means nothing but position.
Read a division as drawer + discipline +sub-discipline — one digit, then two, then one. Two digits for the discipline is not decoration: the widest drawer holds 15 of them, so one digit would not reach.
1000 Humanities
- 1010Performing arts
- 1020Visual arts
- 1030HistoryAlso regarded as a Social science
- 1040Languages and literatureLinguistics listed in Social science
- 1050LawAlso regarded as a Social science
- 1060PhilosophyAlso regarded as the separate, an entry at the highest level of the hierarchy
- 1070Religious studiesAlso regarded as a social science
- 1080Divinity
- 1090Theology
- 1100Religion
2000 Social science
- 2010Anthropology
- 2011Archaeology
- 2020Business
- 2030Economics
- 2040Futurology(also known as future studies or prospective studies)
- 2050Geography
- 2060LinguisticsAlso regarded as a formal science
- 2070Political science
- 2080Psychology
- 2090Sociology
- 2100Interdisciplinary studies
- 2101Area studies
- 2102Ethnic and cultural studies
- 2103Organizational studies
3000 Natural science
- 3010Physical Science
- 3011Space sciences
- 3012Astronomy
- 3013Physics
- 3014Chemistry
- 3015Earth science
- 3020Life science
- 3021Biology
4000 Formal science
- 4010Computer scienceAlso a branch of electrical engineering
- 4020Logic
- 4030Mathematics
- 4031Pure mathematics
- 4032Applied mathematics
- 4033Statistics
5000 Applied science
- 5010Agriculture
- 5020Architecture and design
- 5030Education
- 5040Engineering and technology
- 5041Chemical engineering
- 5042Civil engineering
- 5043Educational technology
- 5044Electrical engineering
- 5045Materials science
- 5046Mechanical engineering
- 5047Systems science
- 5050Environmental studies and forestry
- 5060Family and consumer science
- 5070Human physical performance and recreation
- 5080Journalism, media studies and communication
- 5090Library and museum studies
- 5100Medicine and health
- 5110Military sciences
- 5120Public administration
- 5130Public policy
- 5140Social work
- 5150Transportation
Why the numbers stop here
A positional scheme — one digit per level, all the way down — would need about eleven digits, because one list level in the worked example fans out to 130 siblings. A Dewey-style block allocation fares no better: it offers nine slots per level and fails at the second one immediately.
So the digits stop at the division, and depth is carried by an unbounded suffix instead. That is the trade the scheme makes, and everything else follows from it — including the fact that you will never renumber.How an address is computed →