Md. Code, Local Government § 20–202

(a) This section applies to a political subdivision of the State that is

authorized to impose a gross receipts tax.

(b) A political subdivision of the State may not impose a gross receipts tax

on the gross receipts of any person that are received from a sale of:

(1) advertising space:

(i) in any newspaper, magazine, periodical, program,

directory, or other printed matter published in the State; or

(ii) on any billboard, structure, vehicle, or airborne device

located in the State; or

(2) advertising time on or in connection with any radio or television

broadcast originating in the State.