United States
 
United States Army military police cap (enlisted)
Traditional white MPís cap of the type worn from about 1957 until 1992. Note the thin green and yellow stripe that differentiates this particular cap from those of the Navy Shore Patrol and Air Police. Also, the chinstrap is in shiny vinyl, as opposed to those used on ordinary enlisted caps, which are made of thicker black leather. I have some great MP stories to tell you, but as they say,
discretion is the better part of valor.