Exemption from License Requirement. A buyer licensed by the Potomac River Fisheries Commission may buy seafood in Maryland without purchasing a Maryland license to buy, provided the seafood was caught in the Potomac River. In this regulation the term seafood includes finfish, crabs, lobsters, terrapin, oysters, hard-shell clams, and soft-shell clams. Identification Number. Unless otherwise required by this subtitle, all licensees shall display the identification number provided by the Department on every vessel, vehicle, gear, or place of business used to catch, hold, transport, process, sell, buy, or otherwise deal in seafood. Display of Commercial Identification Number on Vessels and Vehicles. The licensee’s commercial identification number shall be plain vertical block characters of not less than 3 inches in height and shall contrast with the color of the background. All numbers shall be distinctly visible and legible. Display on Vessels. The licensee’s commercial identification number shall be painted or firmly attached to both sides of the vessel. The number shall be positioned on or above the hull, forward, but not on or near the bow, and in such a manner as to be clearly visible to passing boats. Display on Vehicle. The licensee’s commercial identification number shall be painted or firmly attached to the vehicle. The number shall be positioned on the front part of the body on the driver’s side.