That is the Chin Strap but it is only under the Chin in high winds and combat, yea like you would have that hat on in combat. The Head plum was to identify which unit or group (Infantry, artillery, calvary, or command) at a distance. The ribbons were accomplishments, past wars, victories, accolades(on the right chest area). The Sash (across the chest) was for length of service(in position or job) as was the hash marks on the lower sleeve(total length of service). The rank was the chevrons on the upper sleeve. The "Braid" on his right shoulder was for when you are doing a specific chore or duty to distinguish to whom you were attached (You carried the "rank" or importance of the Job that you were attached). The sword signified you were in a command (Officer/NCO) position.

This was how during the earlier conflicts you were able to make a snap judgement by just looking at the uniform to know their Command attachment, medals, current assignment, who assigned, how long in assignment, how long in service, current rank, could you assign them command position.

Yea, I was a B-52 Jock and this was never a case that I needed this much info.

WWG1WGA

So the goofy hat doesn't fall off.