1. Simply leting the superior NCO or Commissioned Officer the you heard, understood and acknowledge the order/instructions.
2. A cute way of hiding disdain for your superiors. Even though you quite literaly mean you heard, understood and acknowledge the orders/instructions. similar to rodger
and fuck you
SFC McDumbass "Get out there and burn the shit! The damn things are overflowing! You got me soldier?"
PVT Joe Snuffie "HOOAH!! Moving time now SFC McDumbass. I'm all over it." See how the "HOOAH" means both yes and fuck you>