This standard gives supplementary requirements for enclosed distribution boards (DBU), which are stationary, type-tested assemblies (TTA) for indoor use, containing protective devices and intended for use either in domestic (household) applications or in other places where unskilled persons have access for their use. This consolidated version consists of the first edition (1990), its amendment 1 (1993) and its amendment 2 (2001). Therefore, no need to order amendments in addition to this publication.