A.k.a. spec, spec sheet, or product spec. A specification is a list of product quality measures that represent a requirement if designated by a user and a guarantee if designated by a producer. Qualities of interest may include one or more characteristics such as density, specific impurities, melting point, boiling point, flash point, or color. The listed qualities generally predict product performance. When referring to a product sample, specification indicates the characteristics of the sample as determined by lab testing. See Technical Data Sheet.