Each site may have a freestanding sign for each frontage not to exceed two signs. Such signs shall not exceed 20 feet in height and 150 square feet in area. The sign shall not be erected closer than 50 feet from the right-of-way line of a public street. If illuminated, the sign shall be nonflashing. Where the building has more than one occupant, all signs must be uniform in size, lettering, design and color. Additional advertising banners, flags, pennants, or similar devices are prohibited. Permit is required.