1.9 In this introductory section (section 1), the genesis of cadre review techniques and development to date have been narrated. Before going on to an understanding of the methodology of cadre review of Group`A' Services, it is necessary to familiarise one self with the concept of a regularly constituted Group `A' Service and its various attributes. Thus, for instance, an organised Service to be viable will have to be sufficiently large and satisfy certain other essential conditions. Section 2 attempts to provide a working definition of the service concept. A complete list of regularly constituted Central Group `A' Services is attached at the end of the Section. The subject matter of the Monograph is discussed in Section 3. The narrative of this Section has been deliberately kept short and brief as the methodology of cadre review is fully explained in the detailed guidelines (Appendix III). The recommendations of the Workshop on cadre review are at Appendix IV. The next section (Section 4) deals with the concept of the non-functional selection grade in group `A' Services, its distinction from the functional selection grade, its rationale, etc. The Monograph concludes in Section 5 with an account of the work done in the area of Group `A' cadre review and the experiences gained.