The Clean Diamond Trade Act was signed into law on July 29, 2003 which prohibits the "importation into, or exportation from, the United States of any rough diamond, from whatever source, unless the rough diamond has been controlled through the Kimberley Process Certification Scheme (KPCS)". Rough diamonds which have become known as conflict diamonds are defined as diamonds used by rebel movements to finance military action opposed to legitimate and internationally recognized governments. The KPCS is a joint government internationally recognized certification system that imposes extensive requirements on its members to enable them to certify shipments of rough diamonds as ‘conflict-free’ and prevent conflict diamonds from entering legitimate trade.