Md. Code, Transp. § 13-617

(a) (1) The owner of any vehicle described in paragraph (2) of this subsection may apply to the Administration for the assignment to that vehicle of a special amateur radio registration number, if the applicant holds an amateur radio station license issued by the Federal Communications Commission. (2) This section applies only as to: (i) A Class A (passenger) vehicle; or (ii) A Class E (truck) vehicle with a one ton or less manufacturer’s rated capacity. (b) Special registration may be issued and continued under this section only if the applicant submits, with the original and each renewal application, proof satisfactory to the Administration that the applicant holds an amateur radio station license issued by the Federal Communications Commission. (c) In addition to the annual registration fee otherwise required by this title, the applicant shall pay an additional annual fee of $5, payable with the original and each renewal application for special registration under this section. (d) A special registration number assigned under this section shall consist of the amateur radio call letters assigned to the applicant by the Federal Communications Commission.