D.C. Mun. Regs. tit. 18 § 1021
Any party desiring to take the deposition of a witness shall make application therefor in the form of a petition to the examiner assigned to the proceeding or, in the event that the examiner has not been assigned, to the Chief Examiner, setting forth the reasons why the deposition should be taken, the name and residence of the witness, the time and place proposed for taking the deposition, and a general description of the matters concerning which the witness will be asked to testify.
If good cause be shown, the examiner may, in his or her discretion, issue an order authorizing the deposition and specifying the witness whose deposition is to be taken, the general scope of the testimony to be taken, the time when, the place where, and the designated officer (authorized to take oaths) before whom the witness is to testify, and the number of copies of the deposition to be supplied.
The order shall be served upon all parties, by the person proposing to take the deposition, a reasonable time in advance of the time fixed for taking testimony.
Witnesses whose testimony is taken by deposition shall be sworn or shall affirm before any questions are put to them.
Each question propounded shall be recorded and the answers shall be taken down in the words of the witness.
Objections to questions or evidence shall be in short form, stating the grounds of objection relied upon, but no transcript filed by the officer shall include argument or debate.
Objections to questions or evidence shall be noted, by the officer, upon the deposition, but he shall have power to decide on the competency or materiality or relevance of evidence, and he shall record the evidence subject to objection.
Objections to questions or evidence not made before the officer shall not be deemed waived unless the ground of the objection is one which might have been obviated or removed if presented at that time.
The testimony shall be reduced to writing by the officer, or under his or her discretion, after which the deposition shall be subscribed to by the witness unless the parties by stipulation waive the signing or the witness is ill, cannot be found or refuses to sign, and certified in usual form by the officer.
If the deposition is not subscribed to by the witness, the officer shall state on record this fact and the reason therefor.
The original deposition and exhibits shall be forwarded to the Hearing Division and shall be filed in the proceedings.
All depositions shall conform to the specifications of §§ 1010, through 1012.
Any fees of a witness, the stenographer or reporter, or the officer designated to take the deposition shall be paid by the person at whose instance the deposition is taken.
The fact that a deposition is taken and filed in a proceeding as provided in this section does not constitute a determination that it is admissible in evidence or that it may be used in the proceeding.
Only that part or the whole of a deposition, which is received in evidence at a hearing, shall constitute a part of the record in the proceeding upon which a decision is based.
D.C. Mun. Regs. Tit. 18, § 1021