NDS:Region Information

Good news first: The DS is fully region free, and in fact is almost the same world wide - except in China and Korea, where Japanese and Italian are respectively replaced with those languages.

But curiously, Chinese software is artificially not compatible with foreign DSes; and even stranger is the fact this misfeature can be bypassed by merely changing the region code at address 0x1D in the header to 00 (international) - or by running the unmodified game on an unmodified DSi or 3DS.

Those consoles do however have region lock for software developed for them, resulting in DSi-enhanced titles (those with aproduct code starting with TWL yet not having a white shell nor "Nintendo DSi" written on top) being region locked on a DSi but not on a DS/Lite. To add to the confusion, the non-Japanese versions of gen 5 Pokemon games (perhaps the most famous DSi-enhanced titles) have most regions except Japan enabled in their header.