Explicit content is a media that affects human psyche and disturbs it. Formatting violent, pornographic and other content should allow control with browser plugins, search crawlers, rss feed readers and other automated tools
Current formats of marking content (SafeSurf, RTA, ICRA, RSAC, PICS and now W3C POWDER) either mark entire page as pornographic using meta tag or headers, or are too complex for webmasters to handle.
Ratings like ESRB, MPAA, PEGI are product specific and centralized, which though does provide confidence, cannot scale with internet media. They are also targeted for specific country and its legislation.
Author has to mark any html element with attribute, based on his subjective rating of content's danger. HTML5 gives attribute data- in free use, so namespace xrate (sort for explicit rating) with integer values (0-100) which represent danger to the viewer (the higher - the bigger), which will also ease filtering. Suggested format is not centralized and thus heavily depends on maintainer and owner of the content. A collective voting system with average or median result as rating value is advised to be used.
data-xrate-violence Violence and its results - weapons, wounds, dead bodies, blood
data-xrate-sex Romantic, erotic, pornographic
data-xrate-nude Level of nudity
data-xrate-disgust Might cause disgust (shit, larvae, decomposition)
data-xrate-asocial Smoking, alcohol, drugs, gambling, prostitution
data-xrate-lang Obscene language
data-xrate-spoiler Story is retold
data-xrate-blink Blinking animation that might cause eplilepsy
data-xrate-camera If application (flash/applet?) gains access to videocamera
data-xrate-malware If resource can cause infection (viruses, trojans etc.) on viewer's machine
<a href="http://meatvideo.com/" data-xrate-violence="100">omg</a> <img src="http://www.tema.ru/jjj/tits/renuar.jpg" data-xrate-nude="60" data-xrate-sex="0" />