(a) Indexes shall be maintained, and revised at least quarterly, for the following Commission records:

(1) Final opinions and orders made in the adjudication of cases.

(2) Statements of policy and interpretation adopted by the Commission and still in force and not published in the Federal Register or official minutes of Commission meetings.

(3) Administrative staff manuals and instructions to staff that affect members of the public.

(b) A copy of each such index is available at cost of duplication from the FOIA Officer.