On the other end of the cams you'll find a 6mm slot cut into each cam, it is offset as well, so when a 6mm rod, or locking bar is placed across the head top surface and into the cams they are correct, use the correct locking pin for the crank web, most don't undo the cams when doing these, I always do personally, makes sure it is correct in case it wasn't prior to doing the belt.
tabetha