JR,

I just assumed it came from regulating the weight of the sail and the
shape that was exposed in a reefed condition.

As Jon's post pointed out Hild had a patent on it. This I had forgotten.

I am a old time LI Sound sailor and always agreed with Herb Hild's
mentality of sails. So when I was transferred to the NW I contacted
Hild's Loft for new sails.

One of Herb's favorite saying was; "Anything that keeps my family and
friends and me off the pointy end of the boat is a good thing!" He is
gone now but I still remember him.