ANSI/AISC 303-16 provides a framework for a common understanding of the acceptable standards when contracting for structural steel. As such, it is useful for everyone associated with construction in structural steel. Unless specific provisions to the contrary are contained in the contract documents, the existing trade practices that are contained therein are considered to be the standard custom and usage of the industry and are thereby incorporated into the relationships between the parties to a contract. The 2016 edition is an ANSI-accredited standard.