Portable storage facilities, including shipping containers, portable on demand storage (PODS®) containers, store-and-move (SAM) containers, buses, heavy-duty trucks and their bodies, semitrailers, freight containers, mobile homes, recreational vehicles and trailers, and any other items or structures deemed by the Zoning Administrator to be substantially the same, and which are no longer in use for their designated purpose, are prohibited from being used as an accessory structure.