Each daily issue of the Federal Register shall be appropriately indexed.

Analytical subject indexes covering the contents of the Federal Register shall be published as currently as practicable and shall be cumulated and separately published at least once each calendar year.

(a) Each daily issue of the Federal Register shall carry a numerical list of the parts of the Code of Federal Regulations specifically affected by documents published in that issue.

(b) Beginning with the second issue of each month, each daily issue shall also carry a cumulated list of the parts affected by documents published during that month.

A monthly list of sections of the Code of Federal Regulations affected shall be separately published on a cumulative basis during each calendar year. The list shall identify the sections of the Code specifically affected by documents published in the Federal Register during the period it covers.

(a) The Director of the Federal Register may order the preparation and publication of indexes, digests, and similar guides, based on laws, Presidential documents, regulatory documents, and notice materials published by the Office, which will serve users of the Federal Register. Indexes, digests, and similar guides will be published yearly or at other intervals as necessary to keep them current and useful.

(b) Each index, digest, and guide is considered to be a special edition of the Federal Register whenever the public need requires special printing or special binding in substantial numbers.