Hi Peter, Although this says that the ``queue`` sub-elements are optional, it may be clearer to add another sentence that explains the device will automatically assign virtqueues to the given ``iothread`` sub-elements when ``queue`` is not given. That answers the question of "what is the behavior of omitting ``queue``?". Each queue can only be assigned to 1 IOThread, so <queue id='1'/> cannot be assigned to multiple IOThreads. Thank you, Stefan