When shelf mounts are attached to wall stud locations, the end brackets fall at the edge of the shelf. The cheaper single slot brackets can twist out from under the shelf, leaving it with no support on the end. They were already installed in my garage so I left them but often have to slide the shelf or push the bracket back under the shelf.

If only there was a little clip that would prevent the bracket from sliding off the end of the shelf and protect the laminate edge banding on the corner. The front of the clip is the height of a 1/2" shelf and the side hangs down just enough to stop the bracket from sliding out. There is a left and right clip with a hole for a #6 screw.