Bill,
The part of the DaVinci code dealing with secret societies is fake. The persons behind the fabrication admitted that it was all fake, the documents, the secrets, everything. There was an interesting show on Discovery some time back called "The Real DaVinci Code", and in it, the book was broken down part by part, and much of it was fake. A few parts are based on real places, but many of the details and events involved are fake. But, of course, if you really want to belive there is a secret society, then you'll readily belive that they had a hand in that show as well to basically deny to existance of any society, thus keeping everything secret once again after the flare-up of popularity.