Scales must be for legal trade and made for commercial use. A legal-for-trade scale will be marked with: A serial number A model number Class III designation on the identification plate or seal All scales put into service in Kentucky after July 1, 2003 must have an NTEP (National Type Evaluation Program) certificate of conformance. Scales that were in use prior to July 1, 2003 are exempt from this regulation Scales marked "Not Legal for Trade" are not acceptable. Baby scales or kitchen scales are two types of scales that are not legal. There is no problem with hanging scales as long as they meet all of the criteria. If you need additional information please consult the Kentucky Farmers' Market Manual.