So Mario Kart DS uses a very secure method of assigning friends; you have to get their 12 digit number, and they have to get yours, and you both have to type it in. There is no way to add someone you randomly race against as a friend, and there’s no chatting method – so really, you HAVE to seek out people’s friends numbers.
And Nintendo, in their infinite wisdom, decided to [ban giving them out on their boards](http://forums.nintendo.com/nintendo/board/message?board.id=mario_kart_ds&message.id=42279):
> You are not permitted to share your NWC id or friend code on a post, in your profile, through PM, or in a sig. Please do not discuss other ways of sharing codes either…This policy was created by Nintendo of America and we have been asked to follow these rules.
To emphasize: There’s no method of chatting or any sort of interraction in game – you race, nothing more. Can’t chat, can’t do anything with voice, you have NO interaction. You can only add friends that you physically have exchanged codes with. And now, you can’t exchange codes through Nintendo’s boards – you can’t even DISCUSS exchanging codes through their boards.
For all this talk about Nintendo “getting” how to do online play, steps like this sure do seem bone-headed.