PICS - Platform for Internet Content Selection
Users set their preferences (or their children's preferences) according to a rating system.
Material can be blocked accordingly.
Any arbitrary rating system can be used including quality or relevance ratings.
Materials can also be selected if search engines index on the PICS labels.
1995 sparked activity towards addressing potentially inappropriate or illegal materials on the Web.
Efforts were focussed at the W3C to develop PICS.
PICS version 1.1 is a Recommendation as of last year
Commercial implementations from Microsoft, IBM, Cyberpatrol, NetShepherd
Joseph M. Reagle