20 C.F.R. § 618.215
(a) When held.
(1) A public hearing must be held in connection with an investigation initiated under § 618.210 whenever, but not later than 10 days after the date of publication in the Federal Register of the notice of receipt of the petition, such a hearing is requested in writing by:
(b) Form of request. A request for public hearing must be filed, in letter format, in the same manner as provided for other documents under § 618.205(d)(2). The request must contain: