To make something Army Proof, you take something that is idiot proof, and make the instructions even more explicit and harder to fuck up.
The MRE heating pack has instructions telling you to lean it on a "Rock or something"
The Claymore mine has "Front towards enemy" written on the front.
These are just a few items that have been made army proof
Something so simplistic even the Army couldn't fuck it up.
Bob-"Man this this bottle top says 'twist' on it!"
Joe-"Shit's ARMY PROOF man."
"Dude, this tank is army proof, it says this side up"