(a) Any individual who is a party to any proceeding before the Judicial Officer, the Board of Contract Appeals or an Administrative Law Judge may appear for himself or by an attorney at law.

(b) The head of any department of the Postal Service may establish such special rules and regulations pertaining to eligibility to practice before such department as he may deem to be necessary or desirable.

(c) Generally, except as provided in § 951.3, any attorney at law who is a member in good standing of the Bar of the Supreme Court of the United States or of the highest court of any State, District, Territory, Protectorate or Possession of the United States, or of the District of Columbia, and is not under any order of any court or executive department of one of the foregoing governmental entities suspending, enjoining, restraining, disbarring, or otherwise restricting him in the practice of law may represent others before the U.S. Postal Service.

(d) When any person acting in a representative capacity appears in person or signs a paper in practice before the Postal Service his personal appearance or signature shall constitute a representation to the Postal Service that under the provisions of this part and the law he is authorized and qualified to represent the particular party in whose behalf he acts. The Postal Service does not generally take formal action or issue any certificate to show that an individual is eligible to practice before it. (See § 951.4.)