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 an 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, a party shall be given an 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. A board, in its discretion, may require additional evidence regarding any matter covered by a stipulation.
D.C. Mun. Regs. tit. 17, r. 17-4110