Willy, those are some of the cabinet door bits. I have others that came as a set in wooden boxes that give the specs on the box. The loose ones I've numbered so I can quickly match the stile and rail cutters with the raised panel cutters that I want to team up for a door and it also helps matching the glass panel cutter adapters and double profile adapters with the correct bits. It gets very confusing and would have been a lot easier to just get them in shaper cutters, but I don't own a shaper.
So, to sum it up, it makes it easier for me to figure out what goes with what and assures me I pulled out the correct bit I wanted to use. Of course, I need to re-mark them every so often.