The World Anti-Doping Agency has assumed responsibility for international doping control from the International Olympic Committee. It has revised, reformed and now presented a new World Anti-Doping Code, which became effective in March 2004, before the Olympic Games Athena's 2004. . The World Anti-Doping Code contains the List of Prohibited Substances and Prohibited Methods. Two important differences from the previous list are that caffeine has been removed from the banned list, and that a new category of 'specified substances' which may produce inadvertent positive tests has been added.
