Specifies basic general purpose timber doors within set height and width limits. It covers flush doors with cellular, intermediate rail, blockboard and particleboard cores, and joinery doors of ledged and braced, frame ledged, panelled and louvred types. It does not cover doors used in fire-resistant door-sets, special purpose doors or doors that are higher or wider than the maximum specified. An appendix gives guidance on information to be given with enquiries and orders.