(a) Any person who is at least 18 years of age and who is not a party to the appeal may serve a subpoena. The means prescribed by applicable state law are sufficient. The party who requested the subpoena, and to whom the subpoena has been issued, is responsible for serving the subpoena.

(b) A subpoena directed to an individual outside the territorial jurisdiction of any court of the United States may be served in the manner described by the Federal Rules of Civil Procedure for service of a subpoena in a foreign country.

(c) A party requesting the presence of a non-federal employee witness must pay that witness' fees and travel expenses in accordance with 5 U.S.C. 1204(b)(3) and 28 U.S.C. 1821. Those fees must be paid or offered to the witness at the time the subpoena is served.