Seems Windows Phone store requires you to upload rating certificates.
Two of them (guess the most important) is easy to receive using their online tool, ESRB and PEGI.
I have uploaded the received PDFs for them and the PEGI in place of DCJTQ (this is also possible).
As I would like the game to be distributed in all possible countries, is there any other certifikate I should get (and easy to get) ?