D.C. Mun. Regs. tit. 16, r. 16-621
A complaint or class of complainants may file with the Director a complaint alleging violation of this chapter; Provided, that no person may file such a complaint with the Department if that person has previously brought that same complaint before a court of law.
All complaints alleging violation of this chapter which are received by the Department, or any other agency or office of the District government, shall be submitted to the Director for preliminary action.
If a complaint remains unresolved after mediation by the Department, or when the Department determines that action involving denial, suspension or revocation of a license or refusal to renew may be appropriate, or when a pattern of complaints arises against a person, the matter shall then be referred, with recommendations for disposition for further action.
D.C. Mun. Regs. tit. 16, r. 16-621