Best voluntary labeling system I've seen yet
 

http://www.freedom-to-tinker.com/archives/000687.html

Couldn't get any easier.

(Basically, any hardcore porn qualifies for prosecution by Ashhahahahaha. Hardcore may loosely be classified has having any of the 3 E's: erection, entry or emission. Though, I'd bet Ashhahahahaha is willing to go after softcore next. I doubt if Ashrhahahahaha approves of any nakedness in any context.)

He is a walking erection with ears.

That man has only been able to reproduce by asexual reproduction.

Didn't say I liked the blogger... , but < ADULTSONLY > < /ADULTSONLY >
beats anything else I've seen proposed.

A friend of mine runs an Evangelical youth group in Post Falls, Idaho. His youth gorup has something to do with a regular Christian youth conference called "Teen Extreme" (the "extreme" is for extreme sports - the event seems to have something to do with BMX biking), whose web-site is located at teenextreme.org. Naturally, there was a porn site with a similar name (I believe it was teenextreme.net). Anyway, a lot of kids looking for this Christian youth conference were getting to this porn site by mistake. The organizers of the event contacted the owners of the porn site and explained the issue to them. They not only voluntarily moved their site, but actually gave their domain to the Teen Extreme conference people, free of charge.

Now, the point of the story, is that, as Professor Felten points out, people in the porn industry generally understand that American culture doesn't have a big problem with them, as long as they don't try to draw in underage kids, and don't show content to adults who don't want to see it. As long as everyone who is looking at the site is of age and is there on purpose, no one (except possibly John Ashhahahahaha, who is a fascist anyway) is going to come after them.

One of the filter companies (cybersitter?) tried promoting an <!--ADULTSONLY--> tag years back. Keeping the label in an html comment meant it didn't require any changes to html standardsit. I think it's unfortunate it didn't catch on. RSACI is a good idea but it's complicated to understand the syntax, and you're supposed to register each site, which is burdonsome for people with thousands of sites. I just want to label the site as porn and be done with it, not assess the language, violence, sexuality and all that of the site. It's also too complicated to just type an RSACI tag from memory, whereas you can easily remember <!--ADULTSONLY--> once you use it a couple times.