Well, the Cahill policy was an unofficial letter that basically promised that as long as nudity was kept to "designated areas" of public beaches naturists would not be ticketed or prosecuted. It was enacted by someone in the Parks Department who is now retired, the details and where to find the actual letter escapes me at the moment and I'm too lazy to google it. lol
We fought a pretty hard-won(ish) battle for San Onofre. If you saw any of the news reports about it I was the guy they kept interviewing with the giant ugly surfboard. Basically when said Parks guy retired, they tried to revoke the cahill policy and start to shut down beaches. This has happened only recently, and some of us are fighting them every step of the way.