In 2009 the Commander of the Republic of Korea Army Support Group (Area IV), South Korea opened a contest for all Soldiers stationed in Korea for the design of the challenge coin. Although his design was not selected, it was one of the top three that were considered.
"A challenge coin is a small coin or medallion (usually military), bearing an organization’s insignia or emblem and carried by the organization’s members. Traditionally, they are given to prove membership when challenged and to enhance morale. In addition, they are also collected by service members. In practice, challenge coins are normally presented by unit commanders in recognition of special achievement by a member of the unit. They are also exchanged in recognition of visits to an organization." - GlobalSecurity.org. Retrieved 10 March 2008