This Recommendation gives guidance on the concepts of Implementation Conformance Statements (ICSs) and System Conformance Statements (SCSs) related to OSI specifications and specifies requirements and gives guidance on the production of ICs, ICs proformas, ICs templates and profile Requirements Lists (RLs). This Recommendation specifies for these documents, the structure, the questions to be asked, the syntax and notation to be used and the semantics of the questions and expected answers. No generic ICs template is provided because of the wide variety of OS1 specifications for which conformance requirements are stated. Nevertheless, this Recommendation provides general requirements that are applicable to any OSI specification. Other than guidance on the relation between Ics and Implementation extra Information for Testing (KIT), requirements and guidance on D(rr are outside the scope of this Recommendation.