pepxl, I assume you got this info from WiiBrew, because I added that way back then... However, X and Z have since appeared as legitimate region codes (not often, though) for games which have two (or three) languages, but not all five or six European (Wii) languages. IIRC, X is usually German & French, Y Italian & Spanish, Z any other languages. This is very strange though, because the SPXP PAL version already has all 5 major languages (The majority of multi-language PAL games do not support the sixth language, Dutch).
They are, however, all PAL and because the main.dol seems to be the same for all regions anyway, this shouldn't matter.