Hmm...
I played a match some time ago with Sgt. Toast or something else.
He screamed "Oh Yeah! 8 STACKS OF FIRE!!" While manning Heavy Flak with Incendiary.
We weren't getting flamed, so I think he meant he put 8 Stacks on the enemy.
I know you can see how badly burnt enemy component is, but can you tell how many stacks?