The ICRA (Internet Content Rating Association), backed by Microsoft, AOL Time Warner and Yahoo, presented its web content labelling scheme in the US today.

The labels allow users to restrict access to websites based on their own criteria and the information in ICRA labels. This, essentially, would allow parents to enforce a censorship system on children's web surfing.

Internet content providers can generate a label, a meta tag to be added to the source code of a web page, by filling in a questionnaire on the ICRA website. The system is free to parents and content providers.

Microsoft, AOL and Yahoo support the initiative and will label their sites, ICRA said in a statement. Some 40,000 websites are already labelled, according to ICRA. Another 160,000 sites that have labels issued by ICRA's frontrunner, the Recreational Software Advisory Council on the Internet (RSACi), are being asked to update.

ICRA is a non-profit-making body founded in early 1999 by a number of internet-related companies and organisations, including Microsoft and AOL. It seeks to promote self-regulation of the internet.

"Our message is to show that there is an alternative to censorious legislation and knee-jerk reactions to hate and porn websites. We promote choice, not censorship," said ICRA chief executive Stephen Balkam in an interview.

The ICRA system hasn't been fully completed. Consumers can use it, but it is "clunky", admitted Balkam.

As part of the promotion effort, Yahoo will ask content providers that submit a web address to Yahooligans, its search engine for children, to label their website, Balkam said.

The ICRA filter will go beyond the self-regulation labels. Third parties, such as the Anti-Defamation League in the US, can make available lists of sites to block. These lists can then be imported into the filter program.