Thanks.
As far as I understand the documentation the place where an item can be put is defined with the item and by default all are authorized.
there's no attribute in inventory that define what can be put in it.
So if you want to create a scabbard you have to forbids all items except melee weapons to be put in it. that's a huge work (or a regex work)
I think a 'category allowed' attribute in inventory can be handy, default all.
Maybe restrict the display of an inventory slot to specific training, commendation, transformation. For example Martial Arts training for scabbard.