The practice of a senior enlisted member presenting a coin or medallion to an individual actually goes back just about 100 years ago in the British Army. During the War of the Boars, the officers were the only ones authorized to receive medals. Whenever an enlisted person did a good job - typically the officer he was assigned to would receive the award. The Regimental SGM would sneak into the officer's tent, cut the medal from the ribbon. He would then call an all hands to formally "shake the hand" of the exceptional soldier, and would "palm the medal" in the soldier's hand without anyone knowing. Today, the coin is pretty much widely used throughout all of the military forces in the world, both as a form of recognition, and even in some cases as a "calling card."