UNIQUE
From Anarchy Online Wiki [AOWiki]
Qualifier UNIQUE in item's description means that you can have only one of these items. That is, you can have only one such item, no matter if it is in your bank, inventory or backpack.
This applies only to the items' id. Threre are a few items with the same name and different ids (like Notum Ring of the Tree), and you can have each one of them, but only in one copy.
