<P> Back at his squadron, it became tradition to ensure that all members carried their medallion or coin at all times . This was accomplished through challenge in the following manner: a challenger would ask to see the medallion, if the challenged could not produce a medallion, they were required to buy a drink of choice for the member who challenged them . If the challenged member produced a medallion, then the challenging member was required to pay for the drink . This tradition continued throughout the war and for many years after the war while surviving members of the squadron were still alive . </P> <P> According to another story, challenge coins date back to World War II and were first used by Office of Strategic Service personnel who were deployed in Nazi held France . Similarly, Jim Harrington proposed a Jolly sixpence club amongst the junior officers of the 107th Infantry . The coins were simply a local coin used as a "bona fides" during a personal meeting to help verify a person's identity . There would be specific aspects such as type of coin, date of the coin, etc. that were examined by each party . This helped prevent infiltration into the meeting by a spy who would have to have advance knowledge of the meeting time and place as well as what coin was to be presented, amongst other signals, as bona fides . </P> <P> While a number of legends place the advent of challenge coins in the post-Korean Conflict era (some as late as the Vietnam War), or even later, Colonel William "Buffalo Bill" Quinn had coins made for those who served in his 17th Infantry Regiment during 1950 and 1951 . </P> <P> Colonel Verne Green, commander of the 10th Special Forces Group - A, embraced the idea . He had a special coin struck with the unit's badge and motto in 1969 . Until the 1980s, his unit was the only unit with an active challenge coin tradition . </P>

What does coin stand for in the military