Average ilvl not calculating right?

[Rongway]

I'm not actually sure... but I always assumed this is only if you don't have an offhand equipped? I.e. if there's nothing in your offhand, then the offhand slot is treated as having an item with the same ilvl as your main hand effectively counting it twice.

GLA/PLD, one-Handed CNJ, and one-handed THM weapons always only count once because it assumes you will be using a shield, whether you are or not.
All two-handed weapons and weapons for any class/job other than those will always count twice.

The divisor will always be 13.