"Fence" means any structural device forming a physical barrier which is so constructed that not less than fifty percent (50%) of the vertical surface is open to permit the transmission of light, air and vision through such surface in a horizontal plane. This shall include wire mesh, steel mesh, chainlink, louvered, stake, and other similar materials. planting shall be regulated to maintain the required open areas in the fence structure. (Ord. 1000 § 6.20, 1955)