Had a rummage through my old Starfire folders and found this. It may have come from Communique originally.
Armoured XO Racks
HT 8 Cost 7 Maximum quantity per unit as XO racks
Code (XOa) Dev. 3500
Armoured XO racks were developed in response to the laser torpedo, which devastates XO racks. An armoured XO rack is not destroyed until one HS of armour, or a single internal system (not by HS), is destroyed. Additionally, the defender may choose to eliminate destroyed XO racks in any order, including unloaded ones first.