“Paul Otlet (b. August 23, 1868, Belgium – December 10, 1944) was the founding father of documentation, the field of study now more commonly referred to as information science. He created the Universal Decimal Classification, one of the most prominent examples of faceted classification. Otlet was responsible for the widespread adoption in Europe of the standard American 3×5 inch index card used until recently in most library catalogs around the world, though largely displaced by the advent of online public access catalogs (OPAC). Otlet wrote numerous essays on how to collect and organize the world’s knowledge, culminating in two books, the Traité de documentation (1934) and Monde: Essai d’universalisme (1935).
Otlet, along with his friend and colleague Henri La Fontaine, founded the now-bankrupt Institut International de Bibliographie in 1895 which later became in English the International Federation for Information and Documentation (FID). In 1910, following a huge international conference, they created the Union of International Associations, which is still located in Brussels. They also created a great international center called at first Palais Mondial (World Palace), later, the Mundaneum to house the collections and activities of their various organizations and institutes.”