Removal, new occupancy, special event or banner signs. Removal or new occupancy signs shall not exceed 10 square feet in area. They shall be removed within 15 days of removal or new occupancy. No outdoor banner, flag, paper, canvas or cloth signs used to advertise a special event shall be erected until the proper permit is obtained. Special event signs may be placed 14 days before the event and removed no later than two days after the event.