I think the image speaks for itself. Or maybe I don’t understand what “bulky” means in CDDA terms.
I think it determines how much extra encumbrance an item would give the player is something else is worn in the same area or over the bulky item.
That description automatically comes with all items that have the
OVERSIZE flag. It means that you can wear it regardless of restrictions from mutations/CBMs/encumbrance but can’t wear anything over it.
Thanks for clarifying it, although the fact it needed clarifying shows that the description is quite murky.