In-game explanation of what the AGC is

About every week people come in the TU discord server (and other places too, I assume) asking about the OFFLINE (AGC) errors that pop up and they pretty much never know what the AGC is or what to do when the error pops up. It would be very helpful if this was explained in the game somehow, like maybe as a short string of text that appears by the unit HUD or something similar.