Major changes to the UDC 1993-2013

Since 1993 UDC has been undergoing major revision. In the process many classes are being completely restructured and modernized. Thousands of new concepts are being added and many obsolete classes are being cancelled. New versions of the UDC Master Reference File are released annually and changes are published in the annual issues of the Extensions & Corrections to the UDC.

This is the summary of the main changes in UDC since Master Reference File was first created in 1993 (see also cancellations and subject coverage statistics). The latest changes in 2011 marked in magenta.

Table 1e - Major revision to the place auxiliaries
(2) Physiographic designation [2002, E&C 24]
(4...)(410)United Kingdom. [1998, E&C 20]
(417)Republic of Ireland. [2001, E&C 23]
(430)Germany. [1997, E&C 19]
(437.3)Czech Republic. [2001, E&C 23]
(437.6)Slovakia. [2004, E&C 26]
(44)France [2011, E&C 33]
(460)Spain [2011, E&C 33]
(469)Portugal. [1998, E&C 20]
(474.2)Estonia. [1998, E&C 20]
(47)Former European USSR. [1995, E&C 17]
(479.1)Former Yugoslavia. [2003, E&C 25]
(492)Netherlands [2011, E&C 33]
(493)Belgium [2011, E&C 33]
(497.4)Slovenia. [2004, E&C 26]
(497.5)Croatia [2003, E&C 25]
(497.7)Former Yugoslavian Republic of Macedonia [2005, E&C 27]
(5...)(517.9)Mongolia [2006, E&C 28]
(519.3)North Korea [2006, E&C 28]
(519.5)South Korea [2006, E&C 28]
(532)Saudi Arabia. [2003, E&C 25]
(533)Yemen. [2003, E&C 25]
(535)Oman. [2003, E&C 25]
(536)East Arabian States. UAR. Qatar. Bahrain. Kuwait. [2003, E&C 25]
(54)States of the Indian subcontinent [2005, E&C 27]
(540)India [2005, E&C 27]
(541.31)Bhutan [2005, E&C 27]
(541.35)Nepal [2005, E&C 27]
(548.7)Sri Lanka [2003, E&C 25]
(548.82)Maldives. [2005, E&C 27]
(549.1)Pakistan. [2002, E&C 24], [2005, E&C 27]
(549.3)Bangladesh. [2002, E&C 24], [2005, E&C 27]
(567)Iraq. [2003, E&C 25]
(569)Syria. [2003, E&C 25]
(569.3)Lebanon. [2003, E&C 25]
(569.5)Jordan. [2003, E&C 25]
(57)Former Asiatic USSR.
(581)Afghanistan. [2001, E&C 23]
(591)Myanmar. [2003, E&C 25]
(593)Thailand. [2003, E&C 25]
(594.9)Timor-Leste (East Timor) [2003, E&C 25]
(596)Cambodia. [2003, E&C 25]
(597)Vietnam. [2003, E&C 25]
(598)Laos [2003, E&C 25]
(6...)(611)Tunisia. [2004, E&C 26]
(612)Libya. [2006, E&C 28]
(620)Egypt. [2004, E&C 26]
(624)Sudan. [2004, E&C 26; 2011, E&C 33]
(624.1)Sudan [2011, E&C 33]
(624.4) South Sudan [2011, E&C 33]
(630)Ethiopia.[2004, E&C 26]
(635)Eritrea. [2004, E&C 26]
(64)Morocco. [2004, E&C 26]
(647)Spanish territories on North African coast [2011, E&C 33]
(649)Canary Islands [2011, E&C 33]
(65)Algeria. [2004, E&C 26]
(661.2)Mauritania. [2004, E&C 26]
(662.1)Mali. [2004, E&C 26]
(662.5)Burkina Faso. [2004, E&C 26]
(664)Sierra Leone. [2004, E&C 26]
(665)Gambia. [2004, E&C 26] [2006, E&C 28]
(665.2)Guinea. [2004, E&C 26]
(666.2)Liberia. [2004, E&C 26]
(666.8)Côte d'Ivoire. [2004, E&C 26]
(667)Ghana. [2004, E&C 26]
(668.1)Togo. [2004, E&C 26]
(668.2)Benin. [2004, E&C 26]
(671.1)Cameroon. [2004, E&C 26]
(671.8)Equatorial Guinea. [2004, E&C 26]
(672.1)Gabon. [2004, E&C 26]
(672.4)Congo. [2004, E&C 26]
(674.1)Central African Republic. [2004, E&C 26]
(674.3)Chad. [2004, E&C 26]
(675)Democratic Republic of Congo. [2004, E&C 26]
(675.97)Burundi. [2004, E&C 26]
(675.98)Rwanda. [2004, E&C 26]
(676.1)Uganda. [2004, E&C 26]
(676.2)Kenya. [2006, E&C 28]
(677.8)Somalia. [2006, E&C 28]
(677.9)Djibuti. [2006, E&C 28]
(678)Tanzania [2006, E&C 28]
(688.3)Botswana. [2004, E&C 26]
(689.1)Zimbabwe. [2006, E&C 28]
(689.4)Zambia [2006, E&C 28]
(689.7)Malawi. [2006, E&C 28]
(669.1)Nigeria. [2003, E&C 25]
(673)Angola [2001, E&C 23]
(691)Madagascar. [2006, E&C 28]
(694.11)Comoros [2003, E&C 25], [2006, E&C 28]
(694.12)Mayotte [2011, E&C 33]
(698.1)Reunion. [2006, E&C 28; [2011, E&C 33]
(698.2)Mauritius. [2006, E&C 28]
(71...)(71)Canada [1999, E&C 21]
(718.9)Saint-Pierre-et-Miquelon [2011, E&C 33]
(72...)(721/727)Mexico. [2002, E&C 24]
(728.1)Guatemala. [2002, E&C 24]
(728.2)Belize. [2002, E&C 24]
(728.3)Honduras. [2002, E&C 24]
(728.4)El Salvador. [2002, E&C 24]
(728.5)Nicaragua. [2002, E&C 24]
(728.6)Costa Rica. [2002, E&C 24]
(728.7)Panama. [2002, E&C 24]
(729. 1)Cuba. [2002, E&C 24]
(729. 2)Jamaica. [2002, E&C 24]
(729. 29)Cayman Islands. [2002, E&C 24]
(729. 3)Dominican Republic. [2002, E&C 24]
(729. 4)Haiti. [2002, E&C 24]
(729. 5)Puerto Rico. [2002, E&C 24]
(729.61)Bahamas. [2002, E&C 24]
(729.68)Turks and Caicos Islands. [2002, E&C 24]
(729.71)Virgin Islands. [2002, E&C 24]
(729.72)British Virgin Islands. [2002, E&C 24]
(729.724)St Kitts and Nevis. [2002, E&C 24]
(729.724.8)Anguilla. [2002, E&C 24]
(729.726)Antigua and Barbuda. [2002, E&C 24]
(729.727)Montserrat. [2002, E&C 24]
(729.74)French territories in Lesser Antilles [2011, E&C 33]
(729.741)Guadeloupe [2002, E&C 24; [2011, E&C 33]
(729.743)Collectivité de Saint-Barthélemy [2011, E&C 33]
(729.744)Saint-Martin [2011, E&C 33]
(729.745)Martinique [2002, E&C 24; [2011, E&C 33]
(729.8)Windward Islands. [2002, E&C 24]
(729.821)Dominica. [2002, E&C 24]
(729.822)Saint Lucia. [2002, E&C 24]
(729.824)Saint Vincent and the Grenadines. [2002, E&C 24]
(729.828)Grenada. [2002, E&C 24]
(729.86)Barbados. [2002, E&C 24]
(729.87)Trinidad and Tobago. [2002, E&C 24]
(729.88)Netherlands territories in Lesser Antilles [2002, E&C 24; 2011, E&C 33]
(729.885)Aruba. [2002, E&C 24; 2011, E&C 33]
(729.9)Bermuda [2002, E&C 24]
(73...)(73)USA [2001, E&C 23]
(8...)(81)Brazil. [2001, E&C 23; 2011, E&C 33]
(82)Argentina. [2001, E&C 23]; [2010, E&C 32]
(83)Chile. [2001, E&C 23]; [2010, E&C 32]
(84)Bolivia. [2001, E&C 23]; [2010, E&C 32]
(85)Peru. [2001, E&C 23]; [2010, E&C 32]
(862)Colombia. [2001, E&C 23]; [2010, E&C 32]
(866)Ecuador. [2001, E&C 23]; [2010, E&C 32]
(87)Venezuela. [2001, E&C 23]; [2010, E&C 32]
(881)Guyana. [2001, E&C 23]; [2010, E&C 32]
(882)French Guiana. [2001, E&C 23]
(883)Suriname. [2001, E&C 23]; [2010, E&C 32]
(893)Paraguay. [2001, E&C 23]; [2010, E&C 32]
(899)Uruguay. [2001, E&C 23]; [2010, E&C 32]
(93...)(932)New Caledonia. [2011, E&C 33]
(94) Australia [1994, E&C 16]
(1/9) A more Extended Place Table - up to the level of former Full UDC editions - is published as a Supplement to E&C 27 (2005). The political section of the table (4/9) is subdivided as far as counties, departments of equivalent units.
Table 1g - Common auxiliaries of time (revised)
".."Table revision included: regularisation of notation, elimination of duplication, removal of concepts that are not aspects of time [2003, E&C 25]
"327"Months [2011, E&C 33]
"61/62"Geological time division [2011, E&C 33]
Table 1i - Point of view, cancelled
 All numbers cancelled, replaced by -02, -05 and colon combinations [1999, E&C 21]
Table 1i - Point of view, cancelled
 All numbers cancelled, replaced by -02, -05 and colon combinations [1999, E&C 21]. See relocation list
-02New table: Common auxiliaries of properties [1999, E&C 21]
-04New table: Common auxiliaries of relations, processes and operations [2003, E&C 25]
-05Persons (revised, and replacing main numbers for personal characteristics throughout UDC) [2001, E&C 23], [2002, E&C 24], [2003, E&C 25]
Main Tables
004New class: Computer science and technology (replacing 681.3, new concepts added in the period 1995-2005) [1995, E&C 17], [2001, E&C 23], [2004, E&C 26]
005New class: Management [2001, E&C 23], [2002, E&C 24]
006.9Standardization of weights, measures and time measurement (now includes metrology, replacing 389, and chronology, replacing 529) [1995, E&C 17]
06Organization of a general nature (revised) [2002, E&C 24]
2Religion. Theology (completely revised class) [2000, E&C 22]: Buddhism [2001, E&C 23], Christianity - Eastern Church [2002, E&C 24], Islam [2006, E&C 28], [2007],[2008], [2009], [2010], [2011, E&C 33]
314Demography (revised) [2002, E&C 24]
316Sociology (new concepts added) [2002, E&C 24], [2006, E&C 28]
33Economics Adding a special auxiliary applicable throughout class 33, replacing a number of small auxiliaries formerly scattered throughout class 33. It incorporates all the concepts previously listed, but in a few cases with altered notations [2005, E&C 27]
338.48Tourism (revised and expanded class, also replacing 379.85) [1999, E&C 21]
364New class: Social welfare (replacing 369) [2000, E&C 22]
37Education (revised, see cancellations 2004) [2004, E&C 26]
39Ethnology (new concepts added)
502/504 Environmental science. Conservation of natural resources completely revised class) [1999, E&C 21]
51Mathematics (510, 512, 517). [2006, E&C 28]
53Physics: 535 [2003, E&C 25]; 530, 535, 536, 538, 539[2006, E&C 28]; [2010, E&C 32]
535Optics (revised, new special auxiliary tables of Visible light. Colours) [2003, E&C 25]
56Palaeontology (includes revisions of 561 'Systematic palaeobotany' and 566/569 . 'Chordata') [1996, E&C 18], [1997, E&C 19 ][2011, E&C 33]
582Systematic botany (revised class) [1997, E&C 19] [2011, E&C 33]
592/599Systematic zoology (revised class) [1996, E&C 18]; [2010, E&C 32]; [2011, E&C 33]
60New class: Biotechnology [2002, E&C 24]
61Medicine (in the process of complete revision) See E&C18 (1996) and further issues
629Transport vehicle engineering (revised) [1997, E&C 19]
64Home economics. Domestic science. Housekeeping (major revision) [2005, E&C 27]
65/651 Management and organization of industry, trade, and communication (revised, see cancellations 2002) [2002, E&C 24]
656Transport and postal services (revised) [2003, E&C 25]
681.13Slot machines. Vending machines. Automats (revised) [2004, E&C 26]
681.3Cancelled and replaced by class 004 [1995, E&C 17]
681.8Technical acoustics (revised) [2003, E&C 25]
684Furniture (revision) [2005, E&C 27]
7.03 Artistic periods and phases (extended coverage of modern styles) [2000, E&C 22]
72Architecture (revised) [2003, E&C 25]
780.6Musical instruments (revised) [2003, E&C 25]
791New class: Cinema. Films (motion pictures) (replacing 791.43) [1999, E&C 21]
913Regional geography (now divided by place auxiliaries) [1994, E&C 16]
94General history (now divided by place auxiliaries) [1994, E&C 16]