Commissioner's Rules & Regulations
Subchapter Part 16 - Special Number Plates
16.5 Restrictions. No plate shall be issued under this Part which:
(a) does not have at least one letter. This provision shall not apply to plates issued to public officers.
(b) has numbers and letters, or any combination thereof, arranged in a format reserved for issuance to specific classes of vehicles other than passenger vehicles.
(c) is assigned for issuance to historical motor vehicles.
(d) consists of six numbers followed by one letter.