47 CFR § 216.2 - Publication of Directives.
(a) We believe, for public awareness and internal administrative purposes, that publication of the current directives is worthwhile. The appendix to this part includes all current NCS Directives.
(b) The Directives are arranged numerically. The first of the hyphenated letters indicates the subject category: “1” for “Organization, Membership and Administration;” “2” for “Plans, Programs and Fiscal Management;” “3” for “Telecommunications Operations;” and “4” for “Technology and Standards.” The second number indicates the sequence of issuance.
(c) In some instances, the appendixes to the directives consist of documents readily accessible elsewhere in the public domain. In the interests of brevity, these documents are referenced rather than reprinted in full.