The term "advertising structure" as used in this chapter is hereby defined to be any board, fence, sign or structure erected or used for advertising purposes, whereon any poster, bill, printing, painting, device or advertising matter of any kind may be placed, stuck, tacked, posted, printed, painted, or fastened; provided, however, this definition shall not include any sign or structure whereon the message is limited to (a) the promotion of political candidates, political issues or other political messages of any nature; or (b) official notices issued by any court or governmental entity or officer; or any sign which has a surface area of less than nine square feet. (Ord. 508 § 1; June 9, 1927: Ord. 4900 § 4; February 23, 1988.)