This Recommendation | International Standard provides: c) a language (the enterprise language) comprising concepts@ structures@ and rules for developing@ representing@ and reasoning about a specification of an ODP system from the enterprise viewpoint (as defined in Rec. ITU-T X.903 | ISO/IEC 10746-3); d) rules which establish correspondences between the enterprise language and the other viewpoint languages (defined in Rec. ITU-T X.903 | ISO/IEC 10746-3) to ensure the overall consistency of a specification. The language is specified to a level of detail sufficient to enable the determination of the compliance of any modelling language to this Recommendation | International Standard and to establish requirements for new specification techniques. This Recommendation | International Standard is intended for use in preparing enterprise viewpoint specifications of ODP systems@ and in developing notations and tools to support such specifications. As specified in clause 5/X.903 | ISO/IEC 10746-3@ an enterprise viewpoint specification defines the purpose@ scope and policies of an ODP system. This Recommendation | International Standard is a refinement and extension of Rec. ITU-T X.903 | ISO/IEC 10746-3@ clauses 5 and 10@ but does not replace them.