Spades, Clubs, Hearts etc,. what’s up with that?
The 101st Airborne used to paint symbols on their helmets, including the 4 suits of playing cards, to identify the regiment they were in. With the chaos of a paradrop, you want to have an easy way to figure out who’s with what unit after the drop, and the helmet insignia helped people identify each other quickly.
Was this mandated by the higher ups, or just a common practice amongst the troops?
It had to be agreed at some level (probably battalion).