Every public place, place of employment, and place established as non-smoking pursuant to Section 17 where smoking is prohibited by this Article, shall have posted at every entrance a conspicuous sign clearly stating that smoking is prohibited. The international "no smoking" symbol consisting of a pictorial representation of a burning cigarette enclosed in a red circle with a red bar diagonally across it shall be considered acceptable under this Section. (Ordinance No. 2006-138)