The provisions of sections two and four shall not apply in connection with any advertisement—
| (a) | which is displayed on a vehicle which is being used on a public road, if it is proved that the main purpose for which that vehicle is being so used is not to display that advertisement; |
| (c) | which a person in the service of the State or of a provincial administration or of anybody which is empowered by a law relating to roads to construct or maintain roads, displays in the performance of his duties in such service; |
| (d) | which is displayed on a public road in accordance with the consent of an authority authorized by a law relating to roads to construct and maintain that road, and which merely indicates that a road or path leading out of the said public road, is a private or farm road or path or is intended for a particular class of traffic or leads to a particular place or to land owned or occupied by a particular person or which conveys merely a warning; |
| (e) | which is displayed on a windmill or on a vehicle or implement or machinery used in connection with farming, if such advertisement consists only of a trade name or the name of the maker or manufacturer of such windmill, vehicle or implement or machinery, or of both such trade name and name, and the chief purpose for which such windmill, vehicle or implement or machinery is used, is not the display of such advertisement. |
