D.C. Mun. Regs. tit. 27, r. 27-106
In a proceeding before the Board, an individual, receiver, or trustee may appear in his or her behalf; a general partner of a partnership may represent the partnership; and an officer of a corporation may represent the corporation. The Office of the Attorney General for the District of Columbia shall represent the District. Independent agencies of the District of Columbia may be represented by agency counsel.
A party may be represented in a proceeding by an attorney at law admitted to practice before the District of Columbia Court of Appeals or before the highest court of the state where he or she resides or maintains an office. An attorney at law employed by the District of Columbia government may represent an agency in accordance with the requirements of Rule 49(c)(4) of the Rules of the District of Columbia Court of Appeals.
An individual appearing before or transacting business with the Board in a representative capacity pursuant to the provisions of Subsection 106.1 may be required to establish his or her authority to act in that capacity.
Notice of Appearance. Each person, including an Assistant Attorney General, representing a party in a case pending before the Board shall file with the Board a written notice of appearance containing the following:
The notice of appearance shall become a part of the record.
Each person who has entered an appearance shall be deemed to continue as representative of the named party unless there is filed with the Board any of the following:
If two or more persons have entered their appearance for a party, service on one representative shall be service on the party, unless one of the representatives has been designated for service.
D.C. Mun. Regs. tit. 27, r. 27-106