Section 15-121-B3 - Numbering pattern to be used(a) The identification numbers awarded under the Connecticut system shall consist of three parts. The first part shall consist of the letters "CT" indicating this state. The second part shall consist of not more than four arabic numerals. The third part shall consist of not more than two letters.(b) The parts shall be separated by a hyphen or an equivalent space. As examples: CT-1-A; CT-1234-AA; CT 56 ZZ.(c) Since the letters "I," "O" and "Q" may be mistaken for arabic numerals, they shall not be used in the suffix.Conn. Agencies Regs. § 15-121-B3