(a) General rule. Except as provided in paragraph (b) of this section, this subpart applies to discovery in proceedings set for hearing under subpart E of this part, and to such other proceedings as the Commission may order.

(b) Exceptions. Unless otherwise ordered by the Commission, this subpart does not apply to:

(1) Requests for information under the Freedom of Information Act, 5 U.S.C. 552, governed by Part 388 of this chapter; or,

(2) Requests by the Commission or its staff who are not participants in a proceeding set for hearing under subpart E of this part to obtain information, reports, or data from persons subject to the Commission's regulatory jurisdiction; or

(3) Investigations conducted pursuant to Part 1b of this chapter.