Maryland Code, State Government § 10-214

(a) Findings of fact must be based exclusively on the evidence of record in the contested case proceeding and on matters officially noticed in that proceeding.

(b) In a contested case, the Office is bound by any agency regulation, declaratory ruling, prior adjudication, or other settled, preexisting policy, to the same extent as the agency is or would have been bound if it were hearing the case.