Universal Decimal Classification - The Application of UDC

The Application of UDC

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 type 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 663.12:57.06 in the article "Yeast Systematics: from Phenotype to Genotype" in the journal Food Technology and Biotechnology (ISSN: 1330-9862)
• UDC code 37.037:796.56, 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" (ISSN 2070-4798).
• UDC code 621.715:621.924:539.3 in the article Residual Stress in Shot-Peened Sheets of AIMg4.5Mn Alloy - in the journal Materials and technology (ISSN 1580-2949).

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. From 1993, a standard version of UDC is maintained and is distributed in a database format: UDC Master Reference File (UDC MRF) which is updated and released annually. The 2010 version of the MRF (released in 2011) contains over 69,000 classes. In the past full printed editions used to have around 220,000 subdivisions.