In 1998, The U.S. Green Building Council created the Leadership in Energy and Environmental Design (LEED) Green Building Rating System. This system provides a set of standards to follow when constructing environmentally-sustainable buildings. This criteria is publicly reviewed by the membership organizations of the USGBC and, if all standards are met, that building then becomes LEED-certified. Individuals may take an accreditation exam and, upon passing, can be considered an Accredited Professional (AP).