PEDIG is named after Marstons Psdigree, a splendid ale brewed nearby at Burton-On-Trent.
Many of of the older waypoints are named after ground 'features' or even people.
Good luck with the application process. It seems to change frequently, but there is lots of useful information and help on here.
Have you had a go at the 'Air Traffic Chief' game yet? No coloured shapes, but loads of planes!