The rules in this subpart govern the procedure with regard to proposals of the Postal Service pursuant to 39 U.S.C. 3661 requesting from the Commission an advisory opinion on changes in the nature of postal services that will generally affect service on a nationwide or substantially nationwide basis. The Rules of General Applicability in subpart A of this part are also applicable to proceedings conducted pursuant to this subpart except that Sec. 3001.21 (Motions); Sec. 3001.25 (Discovery--general policy); Sec. 3001.26 (Interrogatories for purposes of discovery); Sec. 3001.27 (Requests for production of documents or things for the purpose of discovery); Sec. 3001.30 (Hearings); Sec. 3001.33 (Depositions) and Sec. 3001.34 (Briefs) do not apply in proceedings conducted under this subpart.