A subpoena issued by the Commission, at the request of the Commission staff, may be enforced by staff counsel by petition to the appropriate court or district attorney, or both. Any other subpoena issued by the Commission may be enforced by the party requesting the subpoena by petition to the appropriate court.
16 Pa. Code § 42.50
This section cited in 16 Pa. Code § 42.51 (relating to depositions); 16 Pa. Code § 42.54 (relating to production of documents and things and entry for inspection and other purposes); and 16 Pa. Code § 42.103 (relating to subpoena for a hearing upon the merits).