U-trip is the big slow pitch league in my little corner of the Twin Cities metro. I don't do slow pitch, so I don't know about other areas --- I just see the red shirts and dark colored sweat pants
(at least up until a couple of weeks ago... shorts, now) on the umpires as I drive by the slow pitch games.
It is virtually non-existent in fast pitch, except for some teams that sanction U-trip so they can play in the World Series (aka several states tournament). Mike, the translation of the name of the U-trip national is for your benefit!
I've never really paid much attention to their rules, but I have wondered about an organization that apparently considers fastpitch to be a "specialty" sport!