Is this game American or Australian?

[GBAtemp]

Hello I was recently in the process of modding Mariokart ds and upon checking the rom (which I had dumped from my cartridge it reads NTR-AMCE-AUS it was also bought in a local Australian store) I found that the rom loaded onto the cartridge is indeed American this isn’t an issue as original ds games aren’t region locked but I was just curious why it is like this

Source: https://gbatemp.net/threads/is-this-gam ... an.647597/