ZST rules?

Being a fairly newb to the somewhat more obscure Japanese promotions i was wondering what the rules of ZST are. I have seen a couple of Matches, but don't get the rules yet. The fight Gurgel - Imanari, for example has Gurgel wearing gloves and Imanari not. Is that significant to the fight?

if you don't wear gloves, you have to strike open handed - pancrase style.

I've been invited there to do grappling only matches 2 times, and one rule is you cannot close your legs to closed guard. they want the legs open always moving and going for the submission. All the people at ZST and the fans are great! They promise i'm going to be invited back for MMA. Grapplin' ONLY ain't my thing. Their some slick suckers' in there.lol

Didn't ZST tell Rich Clementi that he was "too vale tudo" for them. Which kind of gives you an idea.