Okla. Stat. tit. 47 § 428
Upon the approval and issuance of the application and upon compliance with the terms of this act, the Commission shall issue to the applicant a license as an itinerant merchant. Such license shall be numbered, shall show the amount of fees paid, shall, specifically describe the itinerant merchant and the motor vehicle as they are described in the application, and shall at all times be carried in the cab of the motor vehicle described and shall at all times be subject to inspection by any person authorized to enforce this act. The Commission shall also issue to the itinerant merchant a license plate containing the same number as the license, of distinctive color and size, which shall at all times be displayed on the rear of the motor vehicle described in the license.
Okla. Stat. tit. 47, § 428