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= Locked Items. Cannot be seen in quick stock and cannot
be destroyed or taken by any site event (including zapper).

Or that's what it says at the bottom of the Inventory page, anyway. But when you are submitting items to the Item Drive https://subeta.net/games/drive.php?act=submit then it will take all of the item-type in your inventory, locked or not.

says this is a bug rather than intended behaviour.