If you think you've just created a smut-free world for your class, let me pull you back down to Earth. The rating system you're using in the Content Advisor was devised by the RASC (Recreational Software Advisory Council). This non-profit organization was formed to protect the little ones from offensive stuff and to also protect the rights of free speech. Are you still with me?
RASC is sponsored by the big wigs on the Web. You know...Microsoft, IBM, and Disney. This, of course, makes their rating system among the best available. Cool, right? Well, here's the catch. Sites are rated on a voluntary basis. That's right, RASC leaves it up to Web producers to submit ratings for their own sites. And because site ratings are not mandatory, most sites are NOT rated. Gasp!
Here's the good news. Most high profile sites with adult content, like Playboy, are rated. Whew! Unfortunately, most low profile adult sites, like Bob's Skin Page, are not rated. So, what should you do? SUPERVISE. Let's face it. No matter how good they make IE4 or the Content Advisor, there's no substitute for adult supervision.