D.C. Mun. Regs. tit. 14, § 3907
3907.1 There shall be no intervenors as a matter of right in Rental Accommodations Division proceedings, but intervenors may be permitted to participate in the proceeding prior to a hearing if the proceedings will directly affect their rights or duties and is otherwise appropriate.
3907.2 A request to intervene shall be by motion stating the reasons why intervention should be permitted.
3907.3 While a proceeding is pending before the Rent Administrator, intervenors shall be considered full parties and shall have the same rights and duties as a party to a petition, with the following exceptions.
(a) Intervenors shall not have an independent right to a hearing; and
(b) Intervenors may participate only with respect to issues affecting them that do not require a hearing, as determined by the Rent Administrator.
SOURCE: Notice of Final Rulemaking published at 33 DCR 1336, 1355 (March 7, 1986); as amended by Final Rulemaking published at 68 DCR 012634 (December 3, 2021).