Conn. Gen. Stat. § 14-21

The commissioner shall, upon request, upon the registration of a passenger motor vehicle, motorcycle, camper, motor vehicle used for commercial purposes or passenger and commercial motor vehicle owned by any holder of an amateur radio station license issued by the Federal Communications Commission, issue special number plates bearing the official call letters of such radio station as assigned by the Federal Communications Commission. Each application for such special number plates shall be accompanied by proof satisfactory to the commissioner that the applicant currently holds such a license.