306. (1) The [Municipal Commissioner] may, by notice in writing, require the owner or the person in occupation of any land, building, wall, hoarding or structure to take down or remove within such period as is specified in the notice, any advertisement upon such land, building, wall, hoarding or structure.
(2) if the advertisement is not taken down or removed within such period, the [Municipal Commissioner] may cause it to be taken down or removed, and the expenses reasonably incurred on taken down or removal thereof shall be paid by such owner or person.
(3) The provisions of this section shall not apply to any advertisement which
(a) is exhibited within the window of any building ;
(b) relates to the trade or business carried on within the land or building upon which such advertisement is exhibited or to any sale or letting of such land or building or any effects therein, or to any sale, entertainment or meeting to be held upon or in the same ;
(c) relates to the business of any railway administration ;
(d) is exhibited within any railway station or upon any wall or other property of a railway administration, except any portion of the surface of such wall or property fronting any street.