The confusion likely arises from:
Some late-era DS/DSi and 3DS titles used QR codes on physical marketing materials (like manuals, posters, or website printouts) to unlock special items: Cars 2: The Video Game nintendo ds games qr codes
: This DSiWare application used QR codes to store and share entire programs and games created by the community. The confusion likely arises from: Some late-era DS/DSi