or is it written some where? (base transfer)
No, it is never written anywhere until they have established it (whatrver it is). The reduced pay on base transfer (especially, at the beginning, if it is for a transfer "desired" by the pilot) entrapment has been used before. Some people have been told about it recently and have passed the word along. If you need to know and it is relevant to you, just ask Ryanair what the story is. In fact it would be a very good idea if you are going for command, becuase once you start they will consider you to be commited to taking what you are given once the command is granted - can you imagine the "you mean you don't want this command on our terms" in Oliver Twist "please can I have some more" type outrage!?