Lock an item you want to keep
Open Inventory, find the item and use its context menu’s Lock Item action. Check the lock state before a busy farming, trading or equipment session. Item Lock is attached to the item; it is different from closing the Inventory window.
When an action is rejected
A locked item can be rejected by supported mail, vendor and equipment operations. Do not keep submitting the same action. Read the item’s tooltip and unlock it intentionally before an operation that requires an unlocked item.
Protection scrolls and Item Lock serve different purposes. A lock does not replace the protection required by an upgrade, and it does not promise a successful enhancement.
Find the right item first
Use Inventory Search and Filter to distinguish similar pieces. Compare the name, quantity, enhancements and appearance before changing the lock. Lock the item again after completing the intended operation if you want to keep it protected.