18 C.F.R. § 1308.52 – Issuance.

(a) A deposition subpoena shall not issue except upon the filing of a notice of deposition of the person to be subpoenaed, which notice should normally be filed at least 15 days in advance of the scheduled deposition.
(b) A subpoena for the attendance of a witness at an evidentiary hearing shall not issue except upon the filing of a request for appearance at the hearing of the person to be subpoenaed, which request should normally be filed at least 30 days in advance of the scheduled hearing. The request should state:
1. (1) The name and address of the witness;
2. (2) The general scope of the witness' testimony;
3. (3) The books, records, papers, and other tangible things sought to be produced; and
4. (4) The general relevance of the matters sought to the case.
(c) Upon receipt of a notice of deposition or request for appearance at a hearing, the Hearing Officer shall fill in the name of the witness and sign and issue a subpoena otherwise in blank to the party seeking it, together with a duplicate for proof of service. The party requesting the subpoena shall fill in both copies before service.
(d) Letters rogatory may be issued by the Hearing Officer as provided in 28 U.S.C. 1781-1784.