Md. Code, Tax - General § 9–220

(a) A motor carrier shall display the identification marker for each commercial motor vehicle as the Comptroller requires by regulation.

(b) An identification marker issued under this subtitle remains the property of the State.

(c) The Comptroller may recall an identification marker for a violation of this subtitle or a regulation adopted to carry out this subtitle.

(d) The Comptroller shall provide, by regulation, methods for identification of motor carriers to other motor carriers and the public.