All testimony at a hearing before a board shall be under oath or affirmation.
If any part of the record in any other proceeding previously held before a board, or part of the record in any criminal or civil action, including hearings before any administrative agency, is offered in evidence, a certified true copy of that part shall be presented to the board in the form of an exhibit, unless either of the following requirements is satisfied:
A board shall exclude irrelevant, immaterial, and unduly repetitious evidence.
A board may take official notice, at the request of a party or on its own motion, of the following:
If a board takes official notice of a material fact not appearing in the evidence in the record, it shall give a party the opportunity to show the contrary at the hearing or on motion made within five (5) days after the hearing.
The parties may, by stipulation in writing filed with a board, agree on the facts or any portion thereof involved in a hearing. The parties may also stipulate the testimony that would be given by a witness if the witness were present.
The board may require additional evidence concerning any matter covered by a stipulation.
D.C. Mun. Regs. tit. 17, r. 17-3324