D.C. Mun. Regs. tit. 14, § 1102
1102.1 Each person to whom a license has been issued to conduct a boarding house shall at all times keep a register in which there shall be kept the following information:
1102.2 Each room shall be numbered, and the number shall be indicated in the register.
1102.3 No fictitious names shall be entered in the register.
1102.4 No room shall be assigned to persons of different sexes, except in the case of children accompanied by parent or guardian, unless those persons are registered as husband and wife.
SOURCE: The Housing Regulations of the District of Columbia, 5G DCRR §§ 4104 and 4105, Commissioners' Order 55-1503 (August 11, 1955).