A licensee shall display a license in the way that the Executive Director requires by regulation. A licensee who sells cigarettes through a vending machine: shall place each package of cigarettes in the machine so that when the package is visible the tax stamps required by § 12–304 of the Tax – General Article are also visible; and in the way that the Executive Director requires by regulation, shall: identify each vending machine with a conspicuous label that states the licensee’s name, address, and telephone number; and display on a conspicuous label applicable prohibitions and penalties under § 10–107 of the Criminal Law Article. A licensee shall post a sign in a location that is clearly visible to the consumer that states: “No person under the age of 21 may be sold tobacco products”. The sign required under this subsection shall be written in letters at least one–half inch high.