A type of specification associated with a specific Part Number or group of Part Numbers; sometimes referred to as a “C-spec”. The requirements address whether an acceptable “instance” of a design has, in fact, been produced. In many cases, this type of specification was little more than a reference to a CEI’s identifying drawing (or, in the case of a make-on-assembly item, an index drawing that assigned an Administrative Control Number) and an Acceptance Test Procedure (if the Acceptance criteria are not otherwise included on or referenced by the identifying drawing itself).