The Universal Decimal Classification is a system of library classification developed by the Belgian bibliographers Paul Otlet and Henri La Fontaine at the end of the 19th century. It is based on the Dewey Decimal Classification, but uses auxiliary signs to indicate various special aspects of a subject and relationships between subjects. It thus contains a significant faceted or analytico-synthetic element, and is used especially in specialist libraries. UDC has been modified and extended through the years to cope with the increasing output in all disciplines of human knowledge, and is still under continuous review to take account of new developments.
The documents classified by UDC may be in any form. They will often be literature, i.e. written documents, but may also be in other media such as films, video and sound recordings, illustrations, maps, and realia such as museum pieces.
UDC classifications use Arabic numerals and are based on the decimal system. Every number is thought of as a decimal fraction with the initial decimal point omitted, which determines filing order. For ease of reading, a UDC identifier is usually punctuated after every third digit. Thus, after 61 "Medical sciences" come the subdivisions 611 to 619; under 611 "Anatomy" come its subdivisions 611.1 to 611.9; under 611.1 come all of its subdivisions before 611.2 occurs, and so on; after 619 comes 620. An advantage of this system is that it is infinitely extensible, and when new subdivisions are introduced, they need not disturb the existing allocation of numbers.
A document may be classified under a combination of different categories through the use of additional symbols. For example:
| Symbol | Symbol name | Meaning | Example |
|---|---|---|---|
| + | plus | addition | e.g. 59+636 zoology and animal breeding |
| / | stroke | extension | e.g. 592/599 Systematic zoology (everything from 592 to 599 inclusive) |
| : | colon | relation | e.g. 17:7 Relation of ethics to art |
| [ ] | square brackets | algebraic subgrouping | e.g. 311:[622+669](485) statistics of mining and metallurgy in Sweden (the auxiliary qualifiers 622+669 considered as a unit) |
| = | equals | language | e.g. =111 in English; 59=111 Zoology, in English |
The design of UDC lends itself to machine readability, and the system has been used both with early automatic mechanical sorting devices, and modern library OPACs. A core version of UDC, with 65,000 subdivisions, is now available in database format, and is called the Master Reference File (MRF). The current full version of the UDC has 220,000 subdivisions.[1]
000 Computer science, knowledge & systems
001 Science and knowledge in general. Organization of intellectual work
002 Documentation. Books. Writings. Authorship
003 Writing systems and scripts. Including: signs and symbols
004 Computer science and technology. Computing
004.2 Computer architecture
004.3 Computer hardware
004.4 Software
004.5 Human-computer interaction
004.6 Data
004.7 Computer communication
004.8 Artificial intelligence
004.9 Application-oriented computer-based techniques
005 Management (Revision from 2001)
005.1 Management Theory
005.2 Management agents. Mechanisms. Measures
005.3 Management activities
005.32 Organizational behaviour. Management psychology
005.5 Management operations. Direction
005.6 Quality management. Total quality management (TQM)
005.7 Organizational management (OM)
005.9 Fields of management
005.92 Records management
005.93 Plant management. Physical resources management
005.94 Knowledge management
005.95/.96 Personnel management. Human Resources management
006 Standardization of products, operations, weights, measures and time
007 Activity and organizing. Information. Communication and control theory generally (cybernetics)
008 Civilization. Culture. Progress
009 Humanities. Arts subjects in general
010 Bibliographies
020 Library and information sciences
030 Encyclopedias & books of facts
040 [Unassigned]
050 Magazines, journals, periodicals & serials
060 Associations and organizations & museums
070 News media, journalism, Mass media & publishing
080 Quotations
090 Manuscripts & rare books
100 Philosophy 110 Metaphysics 120 Epistemology 130 Parapsychology & ism 140 Philosophical schools of thought 159.9 Psychology 159.91 Psychophysiology (physiological psychology). Mental physiology 159.92 Mental development and capacity. Comparative psychology 159.93 Sensation. Sensory perception 159.94 Executive functions 159.95 Higher mental processes 159.96 Special mental states and processes 159.97 Abnormal psychology. Insanity. Mental deficiency 159.98 Applied psychology 160 Logic 170 Ethics 180 Ancient, medieval & eastern philosophy 190 Modern western philosophy
200 Religion
21 Prehistoric and primitive religions
22 Religions of the Far East
221 Religions of China
221.3 Taoism
223 Religions of Korea
225 Religions of Japan
23 Religions of the Indian subcontinent
233 Hinduism narrowly
234 Jainism
235 Sikhism
24 Buddhism
241 Hinayana (Theravada) Buddhism
242 Mahayana Buddhism
243 Lamaism
244 Japanese Buddhism
25 Religions of antiquity. Minor cults and religions
252 Religions of Mesopotamia
254 Religions of Iran
257 Religions of Europe
26 Judaism
262 Ashkenazi Judaism
264 Sephardi Judaism
265 Orthodox Judaism
266 Progressive Judaism
267 Modern movements arising from Judaism
27 Christianity
271 Eastern church
272/279 Western church
272 Roman Catholic church
273 Non-Roman Catholic episcopal churches
274 Protestantism generally. Protestants. Dissenters. Puritans
275 Reformed churches
276 Anabaptists
277 Free churches. Non-conformists
278 Other Protestant churches
279 Other Christian movements and churches
28 Islam
282 Sunni. Sunnite Islam
284 Shi'a. Shi'ite Islam
285 Babi-Baha'i
286 Baha'i
29 Modern spiritual movements
210 Philosophy & theory of religion
220 Religions of the Far East
230 Religions of the Indian subcontinent
240 Buddhism
250 Religions of antiquity. Minor cults and religions
260 Judaism
270 Christianity
280 Islam
290 Modern spiritual movements
300 Social sciences, sociology & 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
This section is currently vacant.
500 Science 510 Mathematics 510 Fundamental and general consideration of mathematics 511 Number theory 512 Algebra 514 Geometry 515.1 Topology 517 Analysis 519.1 Combinatorial analysis. Graph theory 520 Astronomy 530 Physics 531 General mechanics. Mechanics of solid and rigid bodies 532 Fluid mechanics in general. Mechanics of liquids (hydromechanics) 533 Mechanics of gases. Aeromechanics. Plasma physics 534 Vibrations. Acoustics 535 Optics 536 Heat. Thermodynamics 537 Electricity. Magnetism. Electromagnetism 539 Physical nature of matter 540 Chemistry 542 Practical laboratory chemistry 543 Analytical chemistry 544 Physical chemistry 546 Inorganic chemistry 547 Organic chemistry 548 Crystallography 550 Earth sciences & geology 560 Fossils & prehistoric life 570 Life sciences; biology 580 Plants (Botany) 590 Animals (Zoology)
600 Technology
610 Medicine & health
611 Medicine
612 Pharmacy
613 Biomedical Sciences
614 Public Health
615 Kinesitherapy - Physical Training
620 Engineering. Technology in general
620 Materials testing. Commercial materials. Power stations. Economics of energy
621 Mechanical engineering in general. Nuclear technology. Electrical engineering. Machinery
621.3 Electrical engineering
622 Mining
623 Military engineering
624 Civil and structural engineering in general
625 Civil engineering and land transport. Railway engineering. Highway engineering
626 Hydraulic engineering in general
627 Natural waterway, port, harbour and shore engineering. Navigational, dredging, salvage and
rescue facilities. Dams and hydraulic power plant
628 Public health engineering. Water. Sanitation. Illuminating engineering
629 Transport vehicle engineering
630 Agriculture
640 Home & family management
650 Management & public relations
660 Chemical engineering
670 Manufacturing
680 Manufacture for specific uses
690 Building & construction
700 Arts 710 Landscaping & area planning 720 Architecture 730 Sculpture, ceramics & metalwork 740 Drawing & decorative arts 750 Painting 760 Graphic arts 770 Photography & computer art 780 Music 790 Sports, games & entertainment
800 General questions. Including: Philology. Rhetoric 810 Linguistics and languages 820 Literature
900 History 910 Geography & travel 920 Biography & genealogy 930 History of ancient world (to ca. 499) 940 History of Europe 950 History of Asia 960 History of Africa 970 History of North America 980 History of South America 990 History of other areas
-1 Place in general -2 Physiographic designation -3 The ancient world -4 Europe -41 British Isles (geographical whole) -410 United Kingdom of Gt Britain and N Ireland -410.1 England -410.3 Wales -410.5 Scotland -410.7 Northern Ireland -415 Ireland (geographical whole) -417 Republic of Ireland -430 Germany -436 Austria -437.1 Czech Republic -437.6 Slovak Republic -438 Poland -439 Hungary -44 France -450 Italy -4549 San Marino -45634 Vatican City -4585 Malta -460 Spain -469 Portugal -47 Former European USSR -470 Russia -48 Scandinavia -480 Finland -481 Norway -485- Sweden -489 Denmark -492 Netherlands -493 Belgium -494 Switzerland -495 Greece -497 Balkan States -5 Asia -6 Africa -61 Tunisia, Libya -7 North and Central America -71 Canada -72 Mexico -728 Central America -729 West Indies -73 USA -74 N E States -75 S E States -76 S Central States -77 N Central States -78 W States -79 Pacific States -8 South America -9 South Pacific and Australia. Arctic. Antarctic
-5 Italians, Romanians, related groups -591 Romanians -5994 Ladins -5998 Sardinians and Corsicans -59982 Sardinians -59984 Corsicans
-21 English language -59 Romanian, Rhaetian, Sardinian, Corsican -5992 Friulian language -5994 Ladin language -5996 Romansch language -59982 Sardinian -59984 Corsican -67 Judeo-Spanish (Ladino) -9455 Sami