 However, its history can be traced back some twenty years before that, to the publication of government procurement standards, such as the United States Department of Defense MIL-Q-9858 standard in 1959, and the UK's Def Stan 05-21 and 05–24.Large organizations that supplied government procurement agencies often had to comply with a variety of quality assurance requirements for each contract awarded, which led the defense industry to adopt mutual recognition of NATO AQAP, MIL-Q, and Def Stan standards.Eventually, industries adopted ISO 9000 instead of forcing contractors to adopt multiple—and often similar—requirements.