No person shall paint, post, place, hang, suspend or affix any advertisement, card, poster, sign, banner or streamer, of any nature, or for any purpose, or cause the same to be done, on or to any curbstone, flagstone or any other portion of any street or sidewalk, or upon any tree or lamppost standing or erected on any public street or other public place, or upon any pole erected upon any public street, or other public place, which pole is used to carry telephone wires or cables, electric light wires or other electric conductors, or to any hydrant, bridge or other public structure within this City; provided however, that nothing herein shall apply to any official notice required by law or ordinance to be posted by public officers.