A product might be verified to comply with a specification or stamped with a specification number. This does not, by itself, indicate that the item is fit for any particular use. The person or group of persons who own the certification scheme (i.e., engineers, trade unions, building code writers, government, industry, etc.) have the responsibility to consider the choice of available specifications, choose the correct ones, set qualification limits, and enforce compliance with those limits. The end users of the product have the responsibility to use the item correctly. Products must be used in accordance with their listing for certification to be effective.