[…]

The national bibliography defined as a bibliographic system or a special national bibliography is relatively new. The phrase "national bibliography" appears in the literature about the middle of the 19th century primarily as a description of the national lists of books. It is not until the first half of the 20th century that a broader definition was recognized. (Madsen, 2000)

An essential decision to extend the definition to all kinds of documents was made by the international conferences arranged by UNESCO in 1950, by UNESCO in cooperation with IFLA (International Federation of Library Associations) in 1977 and by IFLA in November 1998. The results of the conferences are a series of recommendations that have greatly influenced the structure of national bibliographic services throughout the world.

Recommendations by year