D.C. Mun. Regs. tit. 16, r. 16-1512
Any party may serve upon any other party written interrogatories or questions to be answered by the party served or, if the party served is a public or private corporation, a partnership, association, or governmental agency, by an officer or agent, who shall furnish such information as is available to the party.
A party may serve more than thirty (30) interrogatories (each subpart counting as a separate interrogatory) on a given party in a case only with the permission of the Office of Adjudication.
The responding party shall, in writing, answer the interrogatories in the following manner:
The answer shall be signed by the answering party, and the objections shall be signed by the objecting party or counsel for the party.
The party upon whom the interrogatories have been served shall have twenty (20) days in which to answer. Any party who fails to object to an interrogatory within twenty (20) days from the date of service, waives his or her right to object to the interrogatory except in extraordinary circumstances as determined by the Office of Adjudication.
The party serving the interrogatories may file a written response to any objections to the interrogatories no more than five (5) days after service of the objection to interrogatories.
If the party served with the interrogatories fails to answer within the twenty (20) day period, the serving party may file a motion with the Office of Adjudication to compel the served party to answer.
If the Office of Adjudication compels the party to whom the interrogatories are directed to answer the interrogatories, that party shall have ten (10) days from receipt of the Office of Adjudication order in which to do so.
All interrogatories shall be served at least twenty-five (25) days prior to the date scheduled for the hearing.
D.C. Mun. Regs. tit. 16, r. 16-1512