Where a permitted commercial stable, farm market, country store, veterinary clinic or tack shop is maintained, one freestanding sign may be erected on the premises, not exceeding 16 square feet in size, identifying the business, which such sign shall not have more than two sides; shall not exceed six feet in height; and shall not be closer than 10 feet from any lot line or road right-of-way nor obstruct vehicular or pedestrian visibility. One additional sign may be erected on the building facade, not exceeding six square feet in size, identifying the business.