# Universal Decimal Classification: Wikis

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# Encyclopedia

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 over many 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.

The main categories:

A document may be classified under a combination of different categories through the use of additional symbols. For 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 qualifies 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.

## UDC Classes Table

### Main Table

##### 0 Generalities
``` 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
```
##### 1 Philosophy. Psychology
``` 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
```
##### 2 Religion. Theology
``` 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
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
```
##### 3 Social Sciences
``` 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
```
##### 5 Mathematics and natural sciences
``` 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
550 Earth sciences & geology
560 Fossils & prehistoric life
570 Life sciences; biology
580 Plants (Botany)
590 Animals (Zoology)
```
##### 6 Applied sciences. Medicine. Technology
``` 600 Technology
610 Medicine & health
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
```
##### 7 The arts. Recreation. Entertainment. Sport
``` 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
```
##### 8 Language. Linguistics. Literature
``` 800 General questions. Including: Philology. Rhetoric
810 Linguistics and languages
820 Literature
```
##### 9 Geography. Biography. History
``` 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
```

### Table 2 (Geographic Areas, Historical Periods, Persons)

```-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
-61 Tunisia, Libya
-7 North and Central America
-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
```

### Table 5 (Ethnic and National Groups)

```-5 Italians, Romanians, related groups
-591 Romanians
-5998 Sardinians and Corsicans
-59982 Sardinians
-59984 Corsicans
```

### Table 6 (Languages)

```-21 English language
-59 Romanian, Rhaetian, Sardinian, Corsican
-5992 Friulian language
-5996 Romansch language
-59982 Sardinian
-59984 Corsican
-9455 Sami
```