29 C.F.R. § 4905.2
For purposes of this part:
Appearance means testimony or production of documents or other material, including an affidavit, deposition, interrogatory, declaration, or other required written submission.
Compulsory process means any subpoena, order, or other demand of a court or other authority (e.g., an administrative agency or a state or local legislative body) for the appearance of a PBGC employee or former employee.
Employee means any officer or employee of the PBGC, including a special government employee.
Proceeding means any proceeding before any federal, state, or local court; federal, state, or local agency; state or local legislature; or other authority responsible for administering regulatory requirements or adjudicating disputes or controversies, including arbitration, mediation, and other similar proceedings.
Special government employee means an employee of the PBGC who is retained, designated, appointed or employed to perform, with or without compensation, for not to exceed one hundred and thirty days during any three hundred and sixty-five consecutive days, temporary duties either on a full-time or intermittent basis ( 18 U.S.C. 202 ).
29 C.F.R. § 4905.2