Officers get an interface chime whenever their soldiers die, a system flaw that makes subterfuge difficult.
After Carl and Donut silently kill the three guards outside the Prism Kingdom castle, Carl notes that if one of the enemy officers happened to be paying attention, the death of those soldiers would chime on their interface.
He calls it a flaw in the whole system—it makes this sort of subterfuge difficult, since a stealth kill still announces itself up the chain of command. In this case nobody comes charging out the door, and the raid proceeds unnoticed.
Battalion-system quirk that broadcasts stealth kills to enemy officers.