"IMO this level of 'listing' is brought on by lawyers and is really unnecessary."
Here I was thinking it was the manufacturers that pushed this tripe, so they can get you to use thier tool for thier product. Not sure about this, but I believe Phillips sold a license to anyone using the phillips design for screws and thier respective drivers in the early days of them. FYI Robertson predates Phillips and both were invented for the auto industry...
Mark Heller "Well - I oughta....." -Jackie Gleason