They are a cap that fits on top of the fork tube and is held on with a set screw. It's a handle to make preload adjustments possible by hand.
If you look on the bottom side of this one, it shows how it fits over the preload adjustment. Then there is a set screw that holds it on. The three holes are just for decoration.
[ This message was edited by: Hinckley on 2006-01-30 15:54 ]