D.C. Mun. Regs. tit. 31, § 232
232.1 Intervening petitions, answers, amendments, written motions, and all other pleadings shall be served by the parties on the same date that pleading is filed with the Panel.
232.2 When filed, these pleadings shall be accompanied by proof of service upon all parties.
232.3 Proof of service of any pleading shall be by certificate of attorney, affidavit or affirmation, or receipt.
232.4 Service of pleadings shall be made by delivering in person or by depositing in the United States mail, properly addressed, with first-class postage prepaid, one (1) copy of the pleading to each party.
232.5 Service by mail is complete upon mailing.
232.6 Delivery in person to a partnership may be by delivery to any general partner.
232.7 Delivery in person to an association, organization or a corporation may be delivered to any officer.
232.8 When any party or parties shall have appeared by attorney, service shall be made upon the attorney and that service shall be considered service upon that party or parties.
SOURCE: Final Rulemaking published at 34 DCR 6715, 6731 (October 23, 1987).