Party Poker/ Poker.Pro HORSE event

There's a tournament coming up in the UK Party Poker Tour - it says it's Pot Limit HORSE. I have asked but gotten no response. Does anyone have a clue how this would work? My guess is that the HE and Omaha-8 would be Pot Limit and the Stud games Limit. Does anyone know for sure? Pot Limit Stud sounds wrong. But they are running some very odd poker variations, so who knows.