I'm assuming they're for standoff screws like the other six holes in the board, but I'm not sure since they don't have that marking that the other ones do. I'm just asking since I've never actually built a computer before (I've watched it done countless times though, but the mATX mobos I've seen have only six holes, not ten like the GRENADE does.) so I just want to make sure that when the time comes, I'm installing the motherboard correctly cause it seems to require a lot of precision.