Military insignia, symbols used to identify a combat unit, are an ancient custom, predating written records. Originally, symbols were adopted by groups of hunters. It was to build morale, as well as to invoke the aid of gods that were thought to inhabit certain animals. So you had the "Fox band," or "Eagle Crew." They would draw a crude symbol for a fox or eagle on their body or clothing, or wear part of the animal (an eagle feather.) It was good for morale. These hunting organization doubled as combat units when war broke out with another tribe. The latest incarnation of these symbols are special coins, privately minted and containing the unit crest. U.S. Special Forces (Green Berets) began this in the early 1960s. A decade or so earlier, battalions (the basic unit of the U.S. Army) adopted colorful metal crests to be worn on work uniform caps. It wasn't much of a leap to convert these to coins, and coins with units insignia became more and more the rage through the 1970s and 80s. Troops (and some civilians) collect them. It's nice to know that some things have not changed in 20,000 years.