I've read it in more than a few places. Did a quick google search and found this article - check the bottom two paragraphs of page 1 here.

Key points seem to be not have too much camber/draft allowing premature separation and don't let the leach hook. I saw some of the latter at Charlotte Harbor Sunday when it got really light.

With our square-top mains, I think our boats would need a bit more Cunningham to keep the top of the sail open. Apparent wind up high will be coming from a different direction than what we feel down on the boat.

Not sure that its gospel, but its something I'm going to try a bit more of later this year.