Well frankly I think that the rating system already in place by ICRA and SAFESURF should be sufficient for use on any website. I know I have used them for years and it pretty well covers everything there is.

Each website using ICRA can set the ratings for the entire site or for selected pages which makes sense to me.

In addition, this system works with parental filter software currently in existence and unlike the age verification programs being touted elsewhere, both ICRA and SAFESURF are FREE.

It is easy to add to any webpage or site and really, I see no reason to alter the system they employ.

my pennies worth
Ian