No person shall solicit, sell, or peddle any goods, services, wares, merchandise, liquids, or edibles for human consumption, or distribute or post any handbills, circulars, or signs, or use any loud-speakers or other amplifying devices, in any park area, except by concession contract or by special use permit issued by the Department. It shall be the responsibility of any person holding a concession contract or special use permit issued by the Department to display such permit or evidence of contract conspicuously so as to be visible to persons in the vicinity of the operations of such person. [Ord. 126 § 1, 1997.]