A#: APCR (Armor Piercing Composite Rigid) depletion number.Even one of the definitions has 4 abbreviations in it. Love it. By the way, there are also 6 pages of examples and a one page content/introduction, so 19 pages of rules. Triple column pages, but still "only" 19.
X#: Breakdown number of a FT, DC, BAZ, or PSK (weapon is not reapirable) (4.0).
I've finally taken the plunge to learn armor in ASLSK. It's kind of crazy, the biggest part that holds me up - keeping track of how many MP (Movement Points) a vehicle's been seen by an opposing vehicle. This number of MP expended affects the shot. In addition, you really need a way to keep track of the MP used because there are so many different things that can happen during movement.
I'm beginning to think it's the complexity that is drawing me a bit. I've tinkered with OCS, TCS, and read rules to GMT's East Front Series, but I come back to this. But we shall see. Thing is, if you go full ASL, there's even more.
Another potential issue is the "motion", "non-stopped", and "moving" discussion with vehicles...though I think I may have an understanding of this, sort of.
Anyway, Eddy, created a wonderful document, found on Board Game Geek, that is a walk through of an armor game. He's also made them for some of the other ASLSK games. I'm currently going through it step by step to understand the rules. He does an amazing job of stopping and explaining things. This is why I say it's sort of an AAR, I'm not really playing it, but will continue to discuss it as I go. It's tedious, but I feel I'm learning the game so that's a good thing.