I've been making little cheatsheet booklets for my cav troop on things like radio report formats (medevac, call for fire, emergency CAS, etc.), route classification, and so on. It's laminated, so it's waterproof and you can write on it with wet-erase markers. It's also spiral bound and the perfect size to fit in an ACU shoulder pocket. I'm curious though. If you could have a cheatsheet on anything in the army, what would it be? This is the kind of thing that you'd have with you most or all of the time. It can be something army-wide or something job-specific.