The Certification Standard for Steel Building Structures, which started I believe in June 2003. This new standard replaces two separate programs (Conventional Buildings and Complex Buildings) that structural steel fabricators had previously adhered to in order to achieve and maintain AISC certification. Prior to June 2003, fabricators could be audited to either the checklist program at that time or new standard. By the end of this year, fabricators must be certified to the new standard.