I found these when I used this key, `. If you press ` then n you will get a varirity of symbols, but they are random, and it only works on the dsi. It also can be used to put an ` accent on vowels. Here are some of the symbols, °´µ¸±¶¹·²¯³»ÂÂèùìòà . There are some more, but since they are random, I can't get them, I just was for 20 min. lol. And theres your new symbols!
==========================EDIT: I fixed can and put a space in.