It seems to be open as the pics I've seen have all shapes of sails.
BTW, there was a sail number 1100 on the banner at Carolina Sailing club - is that your boat?
There is no restriction on sailmaker or shape - just total area. If you take a look at
http://www.carolinasailingclub.org/xoops/modules/news/article.php?storyid=154, you'll see a few different shapes. I believe the dacron pin-top sails were all made by North (although one could be Kelly or Schurr). All the smoke-color pentex sails were made from SailRite kits. Most were sewn by the skippers themselves.
