Can you clarify this for me, what is a PAL version?
Basically, the European copy of the game that's available for most of Europe, Australia and New Zealand. To put it very simply, a US 3DS can only play US cartridges, PAL 3DS for PAL cartridges, Asia 3DS for Asian cartridges, etc., and this extends to Mystery Codes in the Pokemon games as well. Basically, the codes are region-locked and therefore only redeemable in the region that they originated from (which is why Americans can't claim Japanese events and things like that).