I think it is a bit like a 4.5 tournament and an open tournament.
you have to be a 4.5 to play in the former, but ANYONE can enter the latter..
maybe not the best analogy in history, but do you see what I mean?
5.0 all courter. 2 x Donnay X-Dual Platinum 99s 2 x Donnay Formula 100s (no, really!)
"Tennis isn't easy" - Corners