United States
 
U.S. Naval ROTC cadetís cap
Actually, this may be one of the rarest of the current U.S. military caps. This one is for a U.S. Navy Reserve Officer Training Corps cadet (NROTC). In their last two years of training in college, candidates who have been selected for commissioning in the Marine Corps are allowed to wear special USMC insignia on navy uniforms to show their special status. Essentially, the cap is identical to that from the U.S. Naval Academy at Annapolis, with the characteristic narrow chinstrap. This particular cap was worn by an officer who is now a Marine Corps captain serving as a pilot instructor at the Pensacola Naval Air Station in Florida. Many thanks to Al for finding this one for me.