Within customer premises, the importance of the cabling infrastructure is similar to that of other fundamental building utilities such as heating, lighting and mains power. This International Standard provides: a) users with an application independent generic cabling system and an open market for cabling components; b) users with a flexible cabling scheme such that modifications are both easy and economical; c) building professionals (for example, architects) with guidance allowing the accom-modation of cabling before specific requirements are known; that is, in the initial planning either for construction or refurbishment; d) industry and applications standardisation bodies with a cabling system which supports current products and provides a basis for future product development. It is a consolidated edition, based on edition 1.0 (1995) and including amendments 1:1999 and 2:1999 as well as corrigendum 1 (December 1996) and corrigendum 2 (June 1997).