During World War I, American volunteers from all parts of the country filled the newly formed flying squadrons. Some were wealthy scions attending colleges such as Yale and Harvard who quit in midterm to join the war. In one squadron, a wealthy lieutenant ordered medallions struck in solid bronze carrying the squadron emblem for every member of his squadron. He himself carried his medallion in a small leather sack around his neck.

Shortly after acquiring the medallions, this pilot's aircraft was severely damaged by ground fire. He was forced to land behind enemy lines and was immediately captured by a German Patrol. In order to discourage his escape, the Germans took all of his personal identification except for the small leather pouch around his neck. In the meantime, he was taken to a small French town near the front. Taking advantage of a bombardment that night he donned civilian clothes and escaped. However, he was without personal identification.

He succeeded in avoiding German patrols and reached the front lines. With great difficulty, he crossed no-man's land. Eventually, he stumbled into a French outpost. Unfortunately, the French in this sector of the front had been plagued by saboteurs. They sometimes masqueraded as civilians and wore civilian clothes. Not recognizing the young pilot's American accent, the French thought him to be a saboteur and made ready to execute him. Just in time, he remembered his leather pouch containing the medallion. He showed the medallion to his would-be executioners. His French captors recognized the squadron insignia on the medallion and delayed long enough for him to confirm his identity. Instead of shooting him, they gave him a bottle of wine.

Back with his squadron, it became a tradition to ensure that all members carried their medallion or coin at all times. This was accomplished through a challenge in the following manner, a challenger would ask to see the coin, if he challenger could not produce his coin, he was required to purchase a drink of choice for he member who had challenged him. If the challenged member produced his coin, then the challenging member was required to pay for the drink. This tradition continued throughout the war and for many years after while surviving members of the squadron were still alive.

According to Soldiers Magazine (August '94, story by Maj. Jeanne Fraser Brooks), in the early 1960's, a soldier in the 11th Special Forces Group (SFG), over-stamped some old coins with their emblem, then gave them to unit members.  The 10th SFG soon followed suit with their own coins.

During the Vietnam War, another series of stories is well reported.  The elite front and behind enemy lines fighters, took to a tradition of carrying one special bullet from their combat weapon, carried in the hip pocket, to use for suicide in the event of enemy capture.  On R&R, at the bar or hootch, a soldier could be challenged to show his bullet.  If he could not, he would buy a round of drinks.  If he did produce the bullet, his challenger bought the drinks.  The story goes on the say, in shows of machismo, larger and larger rounds were displayed, getting up to 105mm live cannon shells.  In order to bring safety to the challenge tradition, coins were mandated to be substituted for live rounds.  Such coins were personalized with control numbers and sometimes the person's name.  The challenge tradition remains in effect today, and loss of a prized coin is considered a disgrace.