17 C.F.R. § 240.12b-4

The Commission or its staff may, where it is deemed appropriate, request supplemental information concerning the registrant, a registration statement or a periodic or other report under the Act. This information shall not be required to be filed with or deemed part of the registration statement or report. The information shall be returned to the registrant upon request, provided that:

(a) Such request is made at the time such information is furnished to the staff;

(b) The return of such information is consistent with the protection of investors; and

(c) The return of such information is consistent with the provisions of the Freedom of Information Act (5 U.S.C. 552).

[47 FR 11465, Mar. 16, 1982]