Unless otherwise specified herein or unless the context shall require a contrary construction, the following definitions shall apply to the provisions of this article:
Any sign erected for a temporary or transient purpose, not intended for permanent display, but the term shall not be construed so as to apply to billboards or similar permanent structures which are changed periodically or to signs erected within structures. Examples of casual signs shall be real estate signs, signs advertising yard sales and the like and political advertisements, although this list is not to be deemed all inclusive.
Displaying a casual sign, by whatever means.