Item/Locked
This is a property that you can use if your item is a box or a similar container. You can check the status of the Locked property and allow the player to open the item only if Item/Locked is set to NO.
Item/Opened
This is a property that you can use if your item is capable of being opened; for example, a door. You can check the status of the Opened property and allow the player to pass the door only if the status of Item/Opened is YES.