39 C.F.R. § 952.19
(a) General. Upon written request of either party filed with the Recorder or on his or her own initiative, the presiding officer may issue a subpoena requiring:
(b) Voluntary cooperation. Each party is expected:
(c) Requests for subpoenas.
(1) A request for a subpoena shall to the extent practical be filed:
(d) Motion to quash or modify.
(1) Upon written request by the person subpoenaed or by a party, the presiding officer may:
(e) Form; issuance.
(f)
(4) Service on business persons. Service of any such subpoena may be made upon a partnership, corporation, association, or other legal entity by:
(5) Service on natural persons. Service of any subpoena may be made upon any natural person by: