D.C. Mun. Regs. tit. 4, r. 4-806
An entity covered under the Act shall not require an applicant to state whether the individual is transgender.
If an application form asks for the applicant to identify as male or female, designation by the applicant of a sex that is inconsistent with the applicant's assigned or presumed gender shall not be considered, without more, to be fraudulent or to be a misrepresentation for the purpose of adverse action on the application.
An applicant's giving of a name publicly and consistently used by the applicant, even when the name given is not the applicant's legal name, shall not be grounds for adverse action, if the name given is consistent with the applicant's gender identity or expression. However, where use of a person's legal name is required by law or for a reasonable business purpose, the applicant may be required to disclose it.
An applicant's failure to disclose a change of gender or name (unless specifically required as part of an application process for a reasonable business purpose) shall not be considered grounds for an adverse action.
D.C. Mun. Regs. tit. 4, r. 4-806