By definition, the Universal Decimal Classification (UDC) is an indexing and retrieval language in the form of a classification for the whole of recorded knowledge, in which subjects are symbolized by a code based on Arabic numerals. The UDC was the brain-child of the two Belgians, Paul Otlet and Henry LaFontaine, who began working on their system in 1889, 15 years after Melvil Dewey established the DDC. Otlet and LaFontaine built their system on the foundation of the DDC with Melvil Dewey’s express permission. While Dewey conceived his scheme to be applied to the arrangement of books on shelves, Otlet and LaFontaine, whose fields were Sociology, Law, Statistics, Political Economy, as well as Philology and Literature, were ultimately more interested in journal articles, news items, other related documents, and how to access them. Thus, they required a more detailed system. Fortunately,Dewey agreed to allow them to apply his system to the International Index they had conceived, and by 1895 they had amassed and classified 400,000 cards for their Universal Index. Their system caught on after presenting it to a conference held the same year. Otlet and LaFontaine were required to augment Dewey’s system with numerous devices that they later described as synthetic.
In 1920, a Dutch chemical engineer by the name of Donker Duyvis became the secretary of the editorial panel for the second (French) edition of the UDC, ushering in what was known in the history of the UDC as the authoritative or dictatorial period. Duyvis believed that classification was the necessary liaison between “Efficiency, “”Standardization” and “Information.” With this in mind he initiated the preparation of a new edition of the UDC in 1922/23. Along with Otlet and La Fontaine, he formed the editorial board for the new UDC edition, preparing the second French edition between 1926 and 1931. This edition formed basis for all ensuing versions.
Under Duyvis guidance, the seat of all UDC activities was moved from Brussels to The Hague, and in 1931 the Institut International de Biblographie (IIB), the parent of the UDC, officially became the Institut International de Documentation (IID). Then in 1938, “Documentation” was replaced by “Federation.” The name “Federation International de Documentation” remains to this day.
Since the UDC emerged from a practical need there appears to be no actual principle underlying it, except that it suited the needs for which it was created. Nevertheless, it is in the strictest sense a classification contingent on the analysis of idea contents. It is a comprehensive classification covering most areas of knowledge. Moreover, the UDC is considered a documentary classification that originated from an enumerative system to a faceted one. And while it was created for bibliographic purposes it has proven suitable for libraries. The UDC covers every field of knowledge as an integrated system of...