[TCArknight]

My search-fu is failing me.

Is this an issue that's come up?

I have Natural Armor with a total defDefense of +2, Affecting Arms, Legs and Torso (thingid.armNatural with +1 to it's 1 defense) but I've added the Equipment.StackArmor tag to it and equipped an armor with a +2 defense to A, L and T.

This is the custom item:

  <thing id="armReinfLngCoat" name="Reinforced Long Coat" compset="Armor">
    <fieldval field="defDefense" value="2"/>
    <tag group="ArmorLoc" tag="Torso"/>
    <tag group="ArmorLoc" tag="Legs"/>
    <tag group="ArmorLoc" tag="Arms"/>
    <tag group="ArmorType" tag="ModArmor1"/>
    </thing>

When the natural Armor (with the Equipment.StackArmor and by itself) is equipped, the Armor Value for the hero is +4, without the tag the hero has a +2.