Not sure why running martingales are listed as unconventional in a hunter class. As of December 1, 2015 either standing or running martingales may be used in any hunter class per HU 124.1
A couple of judges have tried to disqualify people using running martingales at some local vhsa shows. Got a real kick out of it when they called 2 big R rated judges to confirm they were illegal. R judges agreed they had no knowlege of them being legal. Internet service comes up and Voila' rules state either can be used in any hunter class. Seems like a lot of folks including lots of judges, stewards, trainers don't know this.
In looking at date on post in 2009 yes, running martingales were unconventional in hunter classes. 2015 both are accepted. I do believe a lot of people are still not aware of these rulings. While waiting for a USEF talent class one very nice jr. rider politely told my student and I she was concerned about us using a running martingale and getting eliminated.
She would have been eliminated had she not taken her standingmartingale off. WIHS jumper eq epecifies running as well.