damagType 0 is listed as Unknown. However. Why not use it for something?? Instead of using STR_UNKNOWN I propose to use STR_DAMAGE_TYPE_NONE and add one entry to the language file STR_DAMAGE_TYPE_NONE: "None"
I suggest game engine or map should have a terrainDamage option to lower terrain damage so for example grenades or rifles can't blow walls or terrain but only high explosives o really high damage.
terrainDamage could work like armour for example
terrainDamage 0.5 gives 50% damage from all sources
Another way to do it is use it as a minimum threshold damage
terrainDamage 80
meaning any damage 80 or less cannot destroy terrain
This could be useful in final maps or fixed maps or special missions that you don't want people cheating going trough walls etc
