While this is of little consequence to the vanilla game (unless someone wanted to expand the Ufopaedia, that is), it is kind of irksome that the Ufopaedia Armor article format (type_id 5) doesn't support Acid and Melee damage - any modifiers are simply not displayed. Same goes for Equipment format (type_id 4) - if a weapon/ammo causes either, it displays "unknown" instead. Could it be perhaps fixed?
(I'm posting it here since it's not a bug per se)