The Bureau of Enforcement shall be a party to proceedings upon designation by the Commission or upon leave to intervene granted pursuant to Sec. 502.68. The Bureau's representative shall be served with copies of all papers, pleadings, and documents in every proceeding in which the Bureau is a party. The Bureau shall actively participate in any proceeding to which it is a party, to the extent required in the public interest, subject to the separation of functions required by section 5(c) of the Administrative Procedure Act. [Rule 42] [78 FR 45071, July 26, 2013]