i dont know how to use
please
If you choose “first” then the dynamic queue that is created is processed before other queues and visa versa if you choose bottom. The best feature there is the parent queue and queue type. This allows you to take control of the dynamic queues that are created and really make them useful. To use this effectively, you need to understand what the queues are doing. You can read more about those here:
http://wiki.mikrotik.com/wiki/Manual:Queue