Okla. Admin. Code § 422:15-5-1
The Executive Director, or his or her designee, with the assistance of staff, shall petition the Commission for an Order of Assessment. The petition shall include a statement of the time, place and nature of the hearing; a statement of the legal authority and jurisdiction under which the hearing is to be held; a reference to the particular sections of the statutes and rules involved; and a short and plain statement of the matters asserted. The petition shall satisfy the requirements of the APA. The petition shall be served on the parties by certified mail, personal service, or other such means as may be permitted in the Oklahoma Pleading Code. The parties shall be provided thirty (30) days notice of an Assessment Hearing.
Okla. Admin. Code § 422:15-5-1