(a) Any party may appear before the Commission and be heard in person or by attorney.(b) The appropriate Bureau Chief(s) of the Commission shall be deemed to be a party to every adjudicatory proceeding (as defined in the Administrative Procedure Act) without the necessity of being so named in the order designating the proceeding for hearing.(c) When, in any proceeding, a pleading is filed on behalf of either the General Counsel or the Chief Engineer, he shall thereafter be deemed a party to the proceeding.(d) Except as otherwise expressly provided in this chapter, a duly authorized corporate officer or employee may act for the corporation in any matter which has not been designated for hearing and, in the discretion of the presiding officer, may appear and be heard on behalf of the corporation in a hearing proceeding.28 FR 12415, Nov. 22, 1963, as amended at 37 FR 8527, Apr. 28, 1972; 44 FR 39180, July 5, 1979; 51 FR 12616, Apr. 14, 1986; 85 FR 63172 , Oct. 6, 2020