“Mobile food service” means the preparation and/or service of food or beverages for immediate consumption to members of the public from a vehicle, cart, or portable vending device when such service occurs on a regular basis at a fixed location and for a period of time longer than fifteen minutes within any six hour period. “Mobile food service” shall not include the service of food or beverages from carts or portable vending devices if such service is conducted as part of a special event, carnival, festival or other organized outdoor activity for a period of four days or less. (Ord. 1990-35 § 1)