Md. Code, Bus. Reg. § 16-209

(a) A licensee shall display a license in the way that the Executive Director requires by regulation. (b) A licensee who sells cigarettes through a vending machine: (1) 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 (2) in the way that the Executive Director requires by regulation, shall: (i) identify each vending machine with a conspicuous label that states the licensee’s name, address, and telephone number; and (ii) display on a conspicuous label applicable prohibitions and penalties under § 10–107 of the Criminal Law Article. (c) (1) 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”. (2) The sign required under this subsection shall be written in letters at least one–half inch high.