Universal Decimal Classification

File:Étiquettes de classement de la CDU - Bibliothèque de la maison Léon Losseau.jpg

Universal decimal classification used at the library of the maison Losseau

Template:Short description The Universal Decimal Classification (UDC) is a bibliographic and library classification representing the systematic arrangement of all branches of human knowledge organized as a coherent system in which knowledge fields are related and inter-linked. The UDC is an analytico-synthetic and faceted classification system featuring detailed vocabulary and syntax that enables powerful content indexing and information retrieval in large collections. Since 1991, the UDC has been owned and managed by the UDC Consortium, a non-profit international association of publishers with headquarters in The Hague, Netherlands.

Unlike other library classification schemes that started their life as national systems, the UDC was conceived and maintained as an international scheme. Its translation into other languages started at the beginning of the 20th century and has since been published in various printed editions in over 40 languages. UDC Summary, an abridged Web version of the scheme, is available in over 50 languages. The classification has been modified and extended over the years to cope with increasing output in all areas of human knowledge, and is still under continuous review to take account of new developments.

Albeit originally designed as an indexing and retrieval system, due to its logical structure and scalability, UDC has become one of the most widely used knowledge organization systems in libraries, where it is used for either shelf arrangement, content indexing or both. UDC codes can describe any type of document or object to any desired level of detail. These can include textual documents and other media such as films, video and sound recordings, illustrations, maps as well as realia such as museum objects.

History

File:La classification Décimale Universelle - Indices composés détaillant l'analyse classificatrice.jpg

An explanatory schema of the Universal Decimal Classification index formation in French, 1920

The UDC was developed by the Belgian bibliographers Paul Otlet and Henri La Fontaine at the end of the 19th century. In 1895, they created the Universal Bibliographic Repertory (Répertoire Bibliographique Universel) (RBU) which was intended to become a comprehensive classified index to all published information. The idea that the RBU should take the form of a card catalogue came from the young American zoologist Herbert Haviland Field, who was at the time himself setting up a bibliographical agency in Zurich, the Concilium Bibliographicum. A means of arranging the entries would be needed, and Otlet, having heard of the Dewey Decimal Classification, wrote to Melvil Dewey and obtained permission to translate it into French. The idea outgrew the plan of mere translation, and a number of radical innovations were made, adapting the purely enumerative classification (in which all the subjects envisaged are already listed and coded) into one which allows for synthesis (that is, the construction of compound numbers to denote interrelated subjects that could never be exhaustively foreseen); various possible relations between subjects were identified, and symbols assigned to represent them. In its first edition in French, Manuel du Répertoire bibliographique universel (1905), the UDC already included many features that were revolutionary in the context of knowledge classifications: tables of generally applicable (aspect-free) concepts—called common auxiliary tables; a series of special auxiliary tables with specific but re-usable attributes in a particular field of knowledge; an expressive notational system with connecting symbols and syntax rules to enable coordination of subjects and the creation of a documentation language proper.

The Universal Bibliographic Repertory grew to more than eleven million records in the period before World War I. The catalogue and its content organized by UDC can still be seen in Mundaneum in Mons, Belgium. In 2013 this catalogue was accepted onto the UNESCO Memory of the World international register, recognising it as documentary heritage of global importance.

Application

UDC is used in around 150,000 libraries in 130 countries and in many bibliographical services which require detailed content indexing. In a number of countries it is the main classification system for information exchange and is used in all types of libraries: public, school, academic and special libraries.

UDC is also used in national bibliographies of around 30 countries. Examples of large databases indexed by UDC include:

• NEBIS (The Network of Libraries and Information Centers in Switzerland) — 2.6 million records
• COBIB.SI (Slovenian National Union Catalogue) — 3.5 million records
• Hungarian National Union Catalogue (MOKKA) — 2.9 million records
• VINITI RAS database (All-Russian Scientific and Technical Information Institute of Russian Academy of Science) with 28 million records
• Meteorological & Geoastrophysical Abstracts (MGA) with 600 journal titles
• PORBASE (Portuguese National Bibliography) with 1.5 million records

UDC has traditionally been used for the indexing of scientific articles which was an important source of information of scientific output in the period predating electronic publishing. Collections of research articles in many countries covering decades of scientific output contain UDC codes. Examples of journal articles indexed by UDC:

• UDC code Template:PreCode in the article "Yeast Systematics: from Phenotype to Genotype" in the journal Food Technology and Biotechnology (Template:Catalog lookup link)
• UDC code Template:PreCode, provided in the article "The game method as means of interface of technical-tactical and psychological preparation in sports orienteering" in the Russian journal "Pedagogico-psychological and medico-biological problems of the physical culture and sport" (Template:Catalog lookup link).
• UDC code Template:PreCode in the article Residual Stress in Shot-Peened Sheets of AIMg4.5Mn Alloy - in the journal Materials and technology (Template:Catalog lookup link).

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. Since 1993, a standard version of UDC has been maintained and distributed in a database format: UDC Master Reference File (UDC MRF) which is updated and released regularly. The 2011 version of the MRF (released in 2012) contains over 70,000 classes. In the past full printed editions used to have around 220,000 subdivisions.

Structure

Notation

A notation is a code commonly used in classification schemes to represent a class, i.e. a subject and its position in the hierarchy, to enable mechanical sorting and filing of subjects. UDC uses Arabic numerals arranged decimally. Every number is thought of as a decimal fraction with the initial decimal point omitted, which determines the filing order. An advantage of decimal notational systems is that they are infinitely extensible, and when new subdivisions are introduced, they need not disturb the existing allocation of numbers. For ease of reading, a UDC notation is usually punctuated after every third digit:

Notation	Caption (Class description)
Template:PreCode	Theoretical problems of elementary particles physics. Theories and models of fundamental interactions
Template:PreCode	Symmetries of quantum physics
Template:PreCode	Conservation laws
Template:PreCode	Translations. Rotations
Template:PreCode	Reflection in time and space
Template:PreCode	Space-time symmetries
Template:PreCode	Internal symmetries
Template:PreCode	Currents
Template:PreCode	Unified field theories
Template:PreCode	Strings

In UDC the notation has two features that make the scheme easier to browse and work with:

• hierarchically expressive – the longer the notation, the more specific the class: removing the final digit automatically produces a broader class code.
• syntactically expressive – when UDC codes are combined, the sequence of digits is interrupted by a precise type of punctuation sign which indicates that the expression is a combination of classes rather than a simple class. For example, the colon in Template:PreCode indicates that there are two distinct notational elements: Template:PreCode Law. Jurisprudence and Template:PreCode Politics. In the following code Template:PreCode, the parentheses and quotes indicate four separate notational elements: Template:PreCode Regional geography, Template:PreCode North Kazakhstan, Template:PreCode 20th century and Template:PreCode Maps (document form).

Basic features and syntax

UDC is an analytico-synthetic and faceted classification. It allows an unlimited combination of attributes of a subject and relationships between subjects to be expressed. UDC codes from different tables can be combined to present various aspects of document content and form, e.g. Template:PreCode History (main subject) of United Kingdom (place) in 20th century (time), a textbook (document form). Or: Template:PreCode Relationship between Education and Religion. Complex UDC expressions can be accurately parsed into constituent elements.

UDC is also a disciplinary classification covering the entire universe of knowledge. This type of classification can also be described as aspect or perspective, which means that concepts are subsumed and placed under the field in which they are studied. Thus, the same concept can appear in different fields of knowledge. This particular feature is usually implemented in UDC by re-using the same concept in various combinations with the main subject, e.g. a code for language in common auxiliaries of language is used to derive numbers for ethnic grouping, individual languages in linguistics and individual literatures. Or, a code from the auxiliaries of place, e.g. Template:PreCode United Kingdom, uniquely representing the concept of United Kingdom can be used to express Template:PreCode Regional geography of United Kingdom and Template:PreCode History of United Kingdom.

Organization

Concepts are organized in two kinds of tables:

• Common auxiliary tables (including certain auxiliary signs). These tables contain facets of concepts representing general recurrent characteristics, applicable over a range of subjects throughout the main tables, including notions such as place, language of the text and physical form of the document, which may occur in almost any subject. UDC numbers from these tables, called common auxiliaries are simply added at the end of the number for the subject taken from the main tables. There are over 15,000 common auxiliaries in UDC.
• The main tables or main schedules containing the various disciplines and branches of knowledge are arranged in 9 main classes, numbered from 0 to 9 (with class 4 being vacant). At the beginning of each class there are also series of special auxiliaries, which express aspects that are recurrent within this specific class. Main tables in UDC contain more than 60,000 subdivisions.

Main classes

• 0 Science and Knowledge. Organization. Computer Science. Information Science. Documentation. Librarianship. Institutions. Publications
• 1 Philosophy. Psychology
• 2 Religion. Theology
• 3 Social Sciences
• 4 vacant
• 5 Mathematics. Natural Sciences
• 6 Applied Sciences. Medicine, Technology
• 7 The Arts. Entertainment. Sport
• 8 Linguistics. Literature
• 9 Geography. History

The vacant class 4 is the result of a planned schedule expansion. This class was freed by moving linguistics into class 8 in the 1960s to make space for future developments in the rapidly expanding fields of knowledge; primarily natural sciences and technology.

Common auxiliary tables

Common auxiliaries are aspect-free concepts that can be used in combination with any other UDC code from the main classes or with other common auxiliaries. They have unique notational representations that make them stand out in complex expressions. Common auxiliary numbers always begin with a certain symbol known as a facet indicator. For example, an equals sign always indicates a language; numbers starting with zero and enclosed in parentheses always indicate a document form. Thus Template:PreCode Textbook and Template:PreCode English can be combined to express, for example, Template:PreCode Textbooks in English. When combined with numbers from the main UDC tables one might get: Template:PreCode Religion textbooks in English or Template:PreCode Mathematics textbooks in English.

Indicator	Table	Concepts
Template:PreCode	1c	Language
Template:PreCode	1d	Form
Template:PreCode	1e	Place
Template:PreCode	1f	Human ancestry, ethnic grouping and nationality
Template:PreCode	1g	Time
Template:PreCode	1k	Properties
Template:PreCode		Materials
Template:PreCode		Relations, processes and operations
Template:PreCode		Persons and personal characteristics

Connecting signs

In order to preserve the precise meaning and enable accurate parsing of complex UDC expressions, a number of connecting symbols are made available to relate and extend UDC numbers. These are:

Symbol	Symbol name	Meaning	Example
Template:PreCode	plus	coordination, addition	Template:PreCode zoology and animal breeding
Template:PreCode	stroke	consecutive extension	Template:PreCode Systematic zoology (everything from 592 to 599 inclusive)
Template:PreCode	colon	relation	Template:PreCode Relation of ethics to art
Template:PreCode	square brackets	subgrouping	Template:PreCode statistics of mining and metallurgy in Sweden (the auxiliary qualifiers Template:PreCode are considered as a unit)
Template:PreCode	asterisk	Introduces non-UDC notation	Template:PreCode Planetology, minor planet Eros (IAU authorized number after the asterisk)
Template:PreCode	alphabetical extension	Direct alphabetical specification	Template:PreCode French literature, works of Molière

Outline

UDC classes in this outline are taken from the Multilingual Universal Decimal Classification Summary (UDCC Publication No. 088) released by the UDC Consortium under the Creative Commons Attribution Share Alike 3.0 license (first release 2009, subsequent update 2012).

Main tables

0 Science and knowledge. Organization. Computer science. Information. Documentation. Librarianship. Institution. Publications

Class	Description
Template:PreCode	Prolegomena. Fundamentals of knowledge and culture. Propaedeutics
Template:PreCode	Science and knowledge in general. Organization of intellectual work
Template:PreCode	Documentation. Books. Writings. Authorship
Template:PreCode	Writing systems and scripts
Template:PreCode	Computer science and technology. Computing
Template:PreCode	Computer architecture
Template:PreCode	Computer hardware
Template:PreCode	Software
Template:PreCode	Human-computer interaction
Template:PreCode	Data
Template:PreCode	Computer communication
Template:PreCode	Artificial intelligence
Template:PreCode	Application-oriented computer-based techniques
Template:PreCode	Management
Template:PreCode	Management Theory
Template:PreCode	Management agents. Mechanisms. Measures
Template:PreCode	Management activities
Template:PreCode	Management operations. Direction
Template:PreCode	Quality management. Total quality management (TQM)
Template:PreCode	Organizational management (OM)
Template:PreCode	Fields of management
Template:PreCode	Records management
Template:PreCode	Plant management. Physical resources management
Template:PreCode	Knowledge management
Template:PreCode	Personnel management. Human Resources management
Template:PreCode	Standardization of products, operations, weights, measures and time
Template:PreCode	Activity and organizing. Information. Communication and control theory generally (cybernetics)
Template:PreCode	Civilization. Culture. Progress
Template:PreCode	Bibliography and bibliographies. Catalogues
Template:PreCode	Librarianship
Template:PreCode	General reference works (as subject)
Template:PreCode	Serial publications, periodicals (as subject)
Template:PreCode	Organizations of a general nature
Template:PreCode	Museums
Template:PreCode	Newspapers (as subject). The Press. Outline of journalism
Template:PreCode	Polygraphies. Collective works (as subject)
Template:PreCode	Manuscripts. Rare and remarkable works (as subject)

1 Philosophy. Psychology

Class	Description
Template:PreCode	Nature and role of philosophy
Template:PreCode	Metaphysics
Template:PreCode	General metaphysics. Ontology
Template:PreCode	Special Metaphysics
Template:PreCode	Philosophy of mind and spirit. Metaphysics of spiritual life
Template:PreCode	Philosophical systems and points of view
Template:PreCode	Kinds of viewpoint. Including: Monism. Dualism. Pluralism. Ontological Materialism. Metaphysical Idealism. Platonism, etc.
Template:PreCode	Psychology
Template:PreCode	Psychophysiology (physiological psychology). Mental physiology
Template:PreCode	Mental development and capacity. Comparative psychology
Template:PreCode	Sensation. Sensory perception
Template:PreCode	Executive functions
Template:PreCode	Higher mental processes
Template:PreCode	Special mental states and processes
Template:PreCode	Abnormal psychology
Template:PreCode	Applied psychology (psychotechnology) in general
Template:PreCode	Logic. Epistemology. Theory of knowledge. Methodology of logic
Template:PreCode	Moral philosophy. Ethics. Practical philosophy

2 Religion. Theology

The UDC tables for religion are fully faceted. The second table below lists special auxiliary numbers that can be used to express attributes (facets) of any specific faith. Any special number can be combined with any religion e.g. Template:PreCode Worship can be used to express, for example, Template:PreCode Worship in Judaism, Template:PreCode Worship in Christianity, or Template:PreCode Worship in Buddhism. The complete special auxiliary tables contain around 2000 subdivisions of various attributes that can be attached to express various aspects of individual faiths to a great level of specificity allowing equal level of detail for every religion.

Main Table

Class	Description
Template:PreCode	Religious systems. Religions and faiths
Template:PreCode	Prehistoric and primitive religions
Template:PreCode	Religions originating in the Far East
Template:PreCode	Religions originating in Indian sub-continent. Hindu religion in the broad sense
Template:PreCode	Buddhism
Template:PreCode	Religions of antiquity. Minor cults and religions
Template:PreCode	Judaism
Template:PreCode	Christianity
Template:PreCode	Islam
Template:PreCode	Modern spiritual movements

Template:PreCode Special auxiliary subdivision for religion

Class	Description
Template:PreCode	Theory and philosophy of religion. Nature of religion. Phenomenon of religion
Template:PreCode	Evidences of religion
Template:PreCode	Persons in religion
Template:PreCode	Religious activities. Religious practice
Template:PreCode	Worship broadly. Cult. Rites and ceremonies
Template:PreCode	Processes in religion
Template:PreCode	Religious organization and administration
Template:PreCode	Religions characterised by various properties
Template:PreCode	History of the faith, religion, denomination or church

3 Social sciences

Class	Description
Template:PreCode	Methods of the social sciences
Template:PreCode	Social questions. Social practice. Cultural practice. Way of life (Lebensweise)
Template:PreCode	Gender studies
Template:PreCode	Sociography. Descriptive studies of society (both qualitative and quantitative)
Template:PreCode	Statistics as a science. Statistical theory
Template:PreCode	Society
Template:PreCode	Demography. Population studies
Template:PreCode	Sociology
Template:PreCode	Politics
Template:PreCode	Economics. Economic science
Template:PreCode	Law. Jurisprudence
Template:PreCode	Public administration. Government. Military affairs
Template:PreCode	Safeguarding the mental and material necessities of life
Template:PreCode	Education
Template:PreCode	Cultural anthropology. Ethnography. Customs. Manners. Traditions. Way of life

4 Currently Vacant

This section is currently vacant.

5 Mathematics. Natural sciences

Class	Description
Template:PreCode	Environmental science. Conservation of natural resources. Threats to the environment and protection against them
Template:PreCode	The environment and its protection
Template:PreCode	Threats to the environment
Template:PreCode	Mathematics
Template:PreCode	Fundamental and general considerations of mathematics
Template:PreCode	Number theory
Template:PreCode	Algebra
Template:PreCode	Geometry
Template:PreCode	Analysis
Template:PreCode	Combinatorial analysis. Graph theory
Template:PreCode	Probability. Mathematical statistics
Template:PreCode	Computational mathematics. Numerical analysis
Template:PreCode	Mathematical cybernetics
Template:PreCode	Operational research (OR): mathematical theories and methods
Template:PreCode	Astronomy. Astrophysics. Space research. Geodesy
Template:PreCode	Physics
Template:PreCode	Mechanics
Template:PreCode	Optics
Template:PreCode	Heat. Thermodynamics. Statistical physics
Template:PreCode	Electricity. Magnetism. Electromagnetism
Template:PreCode	Condensed matter physics. Solid state physics
Template:PreCode	Physical nature of matter
Template:PreCode	Chemistry. Crystallography. Mineralogy
Template:PreCode	Practical laboratory chemistry. Preparative and experimental chemistry
Template:PreCode	Analytical chemistry
Template:PreCode	Physical chemistry
Template:PreCode	Inorganic chemistry
Template:PreCode	Organic chemistry
Template:PreCode	Mineralogical sciences. Crystallography. Mineralogy
Template:PreCode	Earth sciences. Geological sciences
Template:PreCode	Paleontology
Template:PreCode	Biological sciences in general
Template:PreCode	Botany
Template:PreCode	Zoology

6 Applied sciences. Medicine. Technology

Class 6 occupies the largest proportion of UDC schedules. It contains over 44,000 subdivisions. Each specific field of technology or industry usually contains more than one special auxiliary table with concepts needed to express operations, processes, materials and products. As a result, UDC codes are often created through the combination of various attributes. Equally, some parts of this class enumerate concepts to a great level of detail, for example, Template:PreCode Hexagon screws with additional shapes. Including: Flank screws. Collar screws. Cap screws

Class	Description
Template:PreCode	Biotechnology
Template:PreCode	Medical sciences
Template:PreCode	Human biology
Template:PreCode	Hygiene generally. Personal health and hygiene
Template:PreCode	Public health and hygiene. Accident prevention
Template:PreCode	Pharmacology. Therapeutics. Toxicology
Template:PreCode	Pathology. Clinical medicine
Template:PreCode	Surgery. Orthopaedics. Ophthalmology
Template:PreCode	Gynaecology. Obstetrics
Template:PreCode	Engineering. Technology in general
Template:PreCode	Materials testing. Commercial materials. Power stations. Economics of energy
Template:PreCode	Mechanical engineering in general. Nuclear technology. Electrical engineering. Machinery
Template:PreCode	Mining
Template:PreCode	Military engineering
Template:PreCode	Civil and structural engineering in general
Template:PreCode	Civil engineering of land transport. Railway engineering. Highway engineering
Template:PreCode	Hydraulic engineering and construction. Water (aquatic) structures
Template:PreCode	Transport vehicle engineering
Template:PreCode	Agriculture and related sciences and techniques. Forestry. Farming. Wildlife exploitation
Template:PreCode	Forestry
Template:PreCode	Farm management. Agronomy. Horticulture
Template:PreCode	Horticulture in general. Specific crops
Template:PreCode	Animal husbandry and breeding in general. Livestock rearing. Breeding of domestic animals
Template:PreCode	Home economics. Domestic science. Housekeeping
Template:PreCode	Communication and transport industries. Accountancy. Business management. Public relations
Template:PreCode	Telecommunication and telecontrol (organization, services)
Template:PreCode	Graphic industries. Printing. Publishing. Book trade
Template:PreCode	Transport and postal services. Traffic organization and control
Template:PreCode	Accountancy
Template:PreCode	Business management, administration. Commercial organization
Template:PreCode	Publicity. Information work. Public relations
Template:PreCode	Chemical technology. Chemical and related industries
Template:PreCode	Various industries, trades and crafts
Template:PreCode	Industries, crafts and trades for finished or assembled articles
Template:PreCode	Building (construction) trade. Building materials. Building practice and procedure

7 The arts. Recreation. Entertainment. Sport

Main Table

Class	Description
Template:PreCode	Physical planning. Regional, town and country planning. Landscapes, parks, gardens
Template:PreCode	Architecture
Template:PreCode	Plastic arts
Template:PreCode	Drawing. Design. Applied arts and crafts
Template:PreCode	Industrial and domestic arts and crafts. Applied arts
Template:PreCode	Painting
Template:PreCode	Graphic art, printmaking. Graphics
Template:PreCode	Photography and similar processes
Template:PreCode	Music
Template:PreCode	Recreation. Entertainment. Games. Sport
Template:PreCode	Cinema. Films (motion pictures)
Template:PreCode	Theatre. Stagecraft. Dramatic performances
Template:PreCode	Social entertainments and recreations. Art of movement. Dance
Template:PreCode	Board and table games (of thought, skill and chance)
Template:PreCode	Sport. Games. Physical exercises
Template:PreCode	Water sports. Aerial sports
Template:PreCode	Riding and driving. Horse and other animal sports
Template:PreCode	Sport fishing. Sport hunting. Shooting and target sports

Template:PreCode Special auxiliary subdivision for the arts

Class	Description
Template:PreCode	Theory and philosophy of art. Principles of design, proportion, optical effect
Template:PreCode	Art technique. Craftsmanship
Template:PreCode	Artistic periods and phases. Schools, styles, influences
Template:PreCode	Subjects for artistic representation. Iconography. Iconology
Template:PreCode	Applications of art (in industry, trade, the home, everyday life)
Template:PreCode	Various questions concerning art
Template:PreCode	Occupations and activities associated with the arts and entertainment
Template:PreCode	Characteristic features, forms, combinations etc. (in art, entertainment and sport)
Template:PreCode	Performance, presentation (in original medium)

8 Language. Linguistics. Literature

Tables for class 8 are fully faceted and details are expressed through combination with common auxiliaries of language (Table 1c) and a series of special auxiliary tables to indicate other facets or attributes in Linguistics or Literature. As a result, this class allows for great specificity in indexing although the schedules themselves occupy very little space in UDC. The subdivisions of Template:PreCode Languages or Template:PreCode Literature, for example, are derived from common auxiliaries of language Template:PreCode (Table 1c) by substituting a point for the equals sign. Thus Template:PreCode English language (as a subject of a linguistic study) and Template:PreCode English literature derive from Template:PreCode English language. Common auxiliaries of place and time are also frequently used in this class to express place and time facets of Linguistics or Literature, e.g. Template:PreCode English literature of Canada in the 19th century.

Main Table

Class	Description
Template:PreCode	General questions relating to both linguistics and literature. Philology
Template:PreCode	Prosody. Auxiliary sciences and sources of philology
Template:PreCode	Rhetoric. The effective use of language
Template:PreCode	Linguistics and languages
Template:PreCode	Languages Derived from the common auxiliaries of language Template:PreCode (Table 1c) by replacing the equals sign Template:PreCode with prefix Template:PreCode. E.g. Template:PreCode English becomes Template:PreCode Linguistics of English language.
Template:PreCode	All languages natural or artificial
Template:PreCode	Individual natural languages
Template:PreCode	Indo-European languages
Template:PreCode	Indo-Iranian languages
Template:PreCode	Dead languages of unknown affiliation. Caucasian languages
Template:PreCode	Afro-Asiatic, Nilo-Saharan, Congo-Kordofanian, Khoisan languages
Template:PreCode	Ural-Altaic, Palaeo-Siberian, Eskimo-Aleut, Dravidian and Sino-Tibetan languages. Japanese. Korean. Ainu
Template:PreCode	Austro-Asiatic languages. Austronesian languages
Template:PreCode	Indo-Pacific (non-Austronesian) languages. Australian languages
Template:PreCode	American indigenous languages
Template:PreCode	Artificial languages
Template:PreCode	Literature
Template:PreCode	Literatures of individual languages and language families Derived from the common auxiliaries of language Template:PreCode (Table 1c) by replacing the equals sign Template:PreCode with prefix Template:PreCode. E.g. Template:PreCode English becomes Template:PreCode English literature.

Template:PreCode Special auxiliary subdivision for linguistics and languages

Class	Description
Template:PreCode	General linguistics
Template:PreCode	Theory of signs. Theory of translation. Standardization. Usage. Geographical linguistics
Template:PreCode	Mathematical and applied linguistics. Phonetics. Graphemics. Grammar. Semantics. Stylistics
Template:PreCode	Text linguistics, Discourse analysis. Typological linguistics
Template:PreCode	Text linguistics. Discourse analysis
Template:PreCode	Typological linguistics

Template:PreCode Special auxiliary subdivision for literary forms, genres

Class	Description
Template:PreCode	Poetry. Poems. Verse
Template:PreCode	Drama. Plays
Template:PreCode	Fiction. Prose narrative
Template:PreCode	Novels. Full-length stories
Template:PreCode	Short stories. Novellas
Template:PreCode	Essays
Template:PreCode	Oratory. Speeches
Template:PreCode	Letters. Art of letter-writing. Correspondence. Genuine letters
Template:PreCode	Prose satire. Humour, epigram, parody
Template:PreCode	Miscellanea. Polygraphies. Selections
Template:PreCode	Various other literary forms
Template:PreCode	Periodical literature. Writings in serials, journals, reviews
Template:PreCode	History as literary genre. Historical writing. Historiography. Chronicles. Annals. Memoirs

Template:PreCode Special auxiliary subdivision for theory, study and technique of literature

Class	Description
Template:PreCode	Literary schools, trends and movements
Template:PreCode	Literary criticism. Literary studies
Template:PreCode	Comparative literary studies. Comparative literature

9 Geography. Biography. History

Tables for Geography and History in UDC are fully faceted and place, time and ethnic grouping facets are expressed through combination with common auxiliaries of place (Table 1e), ethnic grouping (Table 1f) and time (Table 1g)

Class	Description
Template:PreCode	Archaeology. Prehistory. Cultural remains. Area studies
Template:PreCode	Archaeology
Template:PreCode	Prehistory. Prehistoric remains, artifacts, antiquities
Template:PreCode	Cultural remains of historical times
Template:PreCode	Area studies. Study of a locality
Template:PreCode	Geography. Exploration of the Earth and of individual countries. Travel. Regional geography
Template:PreCode	General questions. Geography as a science. Exploration. Travel
Template:PreCode	General geography. Science of geographical factors (systematic geography). Theoretical geography
Template:PreCode	Physical geography
Template:PreCode	Human geography (cultural geography). Geography of cultural factors
Template:PreCode	Theoretical geography
Template:PreCode	Nonliterary, nontextual representations of a region
Template:PreCode	Regional geography
Template:PreCode	Biographical studies. Genealogy. Heraldry. Flags
Template:PreCode	Biographical studies
Template:PreCode	Genealogy
Template:PreCode	Heraldry
Template:PreCode	Nobility. Titles. Peerage
Template:PreCode	Flags. Standards. Banners
Template:PreCode	History
Template:PreCode	Science of history. Historiography
Template:PreCode	History as a science
Template:PreCode	Methodology of history. Ancillary historical sciences
Template:PreCode	Archivistics. Archives (including public and other records)
Template:PreCode	History of civilization. Cultural history
Template:PreCode	General

Common auxiliary tables

Table 1c: Language

Class	Description
Template:PreCode	Languages (natural and artificial)
Template:PreCode	Natural languages
Template:PreCode	Indo-European languages
Template:PreCode	Indo-European languages of Europe
Template:PreCode	Germanic languages
Template:PreCode	Italic languages
Template:PreCode	Romance languages
Template:PreCode	Greek (Hellenic)
Template:PreCode	Celtic languages
Template:PreCode	Slavic languages
Template:PreCode	Baltic languages
Template:PreCode	Albanian
Template:PreCode	Armenian
Template:PreCode	Indo-Iranian, Nuristani (Kafiri) and dead Indo-European languages
Template:PreCode	Indo-Iranian languages
Template:PreCode	Indic languages
Template:PreCode	Iranian languages
Template:PreCode	Dead Indo-European languages (not listed elsewhere)
Template:PreCode	Dead languages of unknown affiliation. Caucasian languages
Template:PreCode	Dead languages of unknown affiliation, spoken in the Mediterranean and Near East (except Semitic)
Template:PreCode	Caucasian languages
Template:PreCode	Afro-Asiatic, Nilo-Saharan, Congo-Kordofanian, Khoisan languages
Template:PreCode	Afro-Asiatic (Hamito-Semitic) languages
Template:PreCode	Nilo-Saharan languages
Template:PreCode	Congo-Kordofanian (Niger-Kordofanian) languages
Template:PreCode	Khoisan languages
Template:PreCode	Ural-Altaic, Palaeo-Siberian, Eskimo-Aleut, Dravidian and Sino-Tibetan languages. Japanese. Korean. Ainu
Template:PreCode	Ural-Altaic languages
Template:PreCode	Japanese
Template:PreCode	Korean
Template:PreCode	Ainu
Template:PreCode	Palaeo-Siberian languages
Template:PreCode	Eskimo-Aleut languages
Template:PreCode	Sino-Tibetan languages
Template:PreCode	Austro-Asiatic languages. Austronesian languages
Template:PreCode	Austro-Asiatic languages
Template:PreCode	Austronesian languages
Template:PreCode	Indo-Pacific (non-Austronesian) languages. Australian languages
Template:PreCode	Indo-Pacific (non-Austronesian) languages
Template:PreCode	Australian languages
Template:PreCode	American indigenous languages
Template:PreCode	Indigenous languages of Canada, USA and Northern-Central Mexico
Template:PreCode	Indigenous languages of western North American Coast, Mexico and Yucatán
Template:PreCode	Central and South American indigenous languages
Template:PreCode	Ge-Pano-Carib languages. Macro-Chibchan languages
Template:PreCode	Andean languages. Equatorial languages
Template:PreCode	Chaco languages. Patagonian and Fuegian languages
Template:PreCode	Isolated, unclassified Central and South American indigenous languages
Template:PreCode	Artificial languages
Template:PreCode	Artificial languages for use among human beings. International auxiliary languages (interlanguages)
Template:PreCode	Artificial languages used to instruct machines. Programming languages. Computer languages

Table 1d: Form

Main Table

Class	Description
Template:PreCode	Bibliographies
Template:PreCode	Books in general
Template:PreCode	Reference works
Template:PreCode	Non-serial separates. Separata
Template:PreCode	Pamphlets. Brochures
Template:PreCode	Addresses. Lectures. Speeches
Template:PreCode	Theses. Dissertations
Template:PreCode	Personal documents. Correspondence. Letters. Circulars
Template:PreCode	Articles in serials, collections etc. Contributions
Template:PreCode	Newspaper articles
Template:PreCode	Reports. Notices. Bulletins
Template:PreCode	Bibliographic descriptions. Abstracts. Summaries. Surveys
Template:PreCode	Other non-serial separates
Template:PreCode	Serial publications. Periodicals
Template:PreCode	Documents relating to societies, associations, organizations
Template:PreCode	Documents for instruction, teaching, study, training
Template:PreCode	Collected and polygraphic works. Forms. Lists. Illustrations. Business publications
Template:PreCode	Presentation in historical form. Legal and historical sources
Template:PreCode	Presentation in chronological, historical form. Historical presentation in the strict sense
Template:PreCode	Biographical presentation
Template:PreCode	Historical sources
Template:PreCode	Legal sources. Legal documents

Template:PreCode Special auxiliary subdivision for document form

Class	Description
Template:PreCode	Documents according to physical, external form
Template:PreCode	Documents according to method of production
Template:PreCode	Handwritten documents (autograph, holograph copies). Manuscripts. Pictorial documents (drawings, paintings)
Template:PreCode	Machine-readable documents
Template:PreCode	Documents according to stage of production
Template:PreCode	Documents for particular kinds of user
Template:PreCode	Documents according to level of presentation and availability
Template:PreCode	Supplementary matter issued with a document
Template:PreCode	Separately issued supplements or parts of documents

Table 1e: Place

Main Table

Class	Description
Template:PreCode	Place and space in general. Localization. Orientation
Template:PreCode	Universal as to place. International. All countries in general
Template:PreCode	Physiographic designation
Template:PreCode	Ecosphere
Template:PreCode	Surface of the Earth in general. Land areas in particular. Natural zones and regions
Template:PreCode	Above sea level. Surface relief. Above ground generally. Mountains
Template:PreCode	Below sea level. Underground. Subterranean
Template:PreCode	Natural flat ground (at, above or below sea level). The ground in its natural condition, cultivated or inhabited
Template:PreCode	Oceans, seas and interconnections
Template:PreCode	Inland waters
Template:PreCode	The world according to physiographic features
Template:PreCode	Places of the ancient and mediaeval world
Template:PreCode	Ancient China and Japan
Template:PreCode	Ancient Egypt
Template:PreCode	Ancient Roman Province of Judaea. The Holy Land. Region of the Israelites
Template:PreCode	Ancient India
Template:PreCode	Medo-Persia
Template:PreCode	Regions of the so-called barbarians
Template:PreCode	Italia. Ancient Rome and Italy
Template:PreCode	Ancient Greece
Template:PreCode	Other regions. Ancient geographical divisions other than those of classical antiquity
Template:PreCode	Countries and places of the modern world
Template:PreCode	Europe
Template:PreCode	Asia
Template:PreCode	Africa
Template:PreCode	North and Central America
Template:PreCode	South America
Template:PreCode	States and regions of the South Pacific and Australia. Arctic. Antarctic

Template:PreCode Special auxiliary subdivision for boundaries and spatial forms of various kinds

Class	Description
Template:PreCode	Zones
Template:PreCode	Orientation. Points of the compass. Relative position
Template:PreCode	East. Eastern
Template:PreCode	South. Southern
Template:PreCode	South-west. South-western
Template:PreCode	West. Western
Template:PreCode	North. Northern
Template:PreCode	Relative location, direction and orientation
Template:PreCode	Lowest administrative units. Localities
Template:PreCode	Dependent or semi-dependent territories
Template:PreCode	States or groupings of states from various points of view
Template:PreCode	Places and areas according to privacy, publicness and other special features
Template:PreCode	Location. Source. Transit. Destination
Template:PreCode	Regionalization according to specialized points of view

Table 1f: Human ancestry and grouping

They are derived mainly from the common auxiliaries of language Template:PreCode (Table 1c) and so may also usefully distinguish linguistic-cultural groups. For example Template:PreCode English is used to represent Template:PreCode English speaking peoples.

Class	Description
Template:PreCode	Human ancestry groups
Template:PreCode	European Continental Ancestry Group
Template:PreCode	Asian Continental Ancestry Group
Template:PreCode	African Continental Ancestry Group
Template:PreCode	Oceanic Ancestry Group
Template:PreCode	American Native Continental Ancestry Group
Template:PreCode	Linguistic-cultural groups, ethnic groups, peoples [derived from Table 1c]
Template:PreCode	Peoples associated with particular places E.g. Template:PreCode Anglophone population of Canada

Table 1g: Time

Class	Description
Template:PreCode	Dates and ranges of time (CE or AD) in conventional Christian (Gregorian) reckoning
Template:PreCode	First millennium CE
Template:PreCode	Second millennium CE
Template:PreCode	Third millennium CE
Template:PreCode	Time divisions other than dates in Christian (Gregorian) reckoning
Template:PreCode	Conventional time divisions and subdivisions: numbered, named, etc.
Template:PreCode	Duration. Time-span. Period. Term. Ages and age-groups
Template:PreCode	Periodicity. Frequency. Recurrence at specified intervals.
Template:PreCode	Geological, archaeological and cultural time divisions
Template:PreCode	Geological time division
Template:PreCode	Archaeological, prehistoric, protohistoric periods and ages
Template:PreCode	Time reckonings: universal, secular, non-Christian religious
Template:PreCode	Universal time reckoning. Before Present
Template:PreCode	Secular time reckonings other than universal and the Christian (Gregorian) calendar
Template:PreCode	Dates and time units in non-Christian (non-Gregorian) religious time reckonings
Template:PreCode	Phenomena in time. Phenomenology of time

Table 1k: General characteristics

Class	Description
Template:PreCode	Common auxiliaries of properties
Template:PreCode	Properties of existence
Template:PreCode	Properties of magnitude, degree, quantity, number, temporal values, dimension, size
Template:PreCode	Properties of shape
Template:PreCode	Properties of structure. Properties of position
Template:PreCode	Properties of arrangement
Template:PreCode	Properties of action and movement
Template:PreCode	Operational properties
Template:PreCode	Properties of style and presentation
Template:PreCode	Properties derived from other main classes
Template:PreCode	Common auxiliaries of materials
Template:PreCode	Naturally occurring mineral materials
Template:PreCode	Manufactured mineral-based materials
Template:PreCode	Metals
Template:PreCode	Materials of mainly organic origin
Template:PreCode	Macromolecular materials. Rubbers and plastics
Template:PreCode	Textiles. Fibres. Yarns. Fabrics. Cloth
Template:PreCode	Other materials
Template:PreCode	Common auxiliaries of relations, processes and operations
Template:PreCode	Phase relations
Template:PreCode	General processes
Template:PreCode	Processes of existence
Template:PreCode	Processes related to position, arrangement, movement, physical properties, states of matter
Template:PreCode	General operations and activities
Template:PreCode	Common auxiliaries of persons and personal characteristics
Template:PreCode	Persons as agents, doers, practitioners (studying, making, serving etc.)
Template:PreCode	Persons as targets, clients, users (studied, served etc.)
Template:PreCode	Persons according to age or age-groups
Template:PreCode	Persons according to ethnic characteristics, nationality, citizenship etc.
Template:PreCode	Persons according to gender and kinship
Template:PreCode	Persons according to constitution, health, disposition, hereditary or other traits
Template:PreCode	Persons according to occupation, work, livelihood, education
Template:PreCode	Persons according to social class, civil status

See also

Classifications based on UDC

• BBC LonClass

Other faceted classifications

• Bliss bibliographic classification
• Colon classification

Other library classifications

• Dewey Decimal Classification
• Library of Congress Classification
• Chinese Library Classification
• Harvard-Yenching Classification

External links

• Universal Decimal Classification Consortium
  • About Universal Decimal Classification
  • Multilingual UDC Summary
  • UDC Linked Data