The regulation was announced on July 18

As all eyes focus on the imminent opening of the Beijing Olympics, all public security, web monitoring and related state organs are given special security and defense work. We synopsize here:

1. All websites must pay meticulous attention to all online content, to guard against any unhealthy content and sensitive news. Categories that must be identified and removed include but are not limited to the following:
a. Pornography and politically reactionary news content are strictly forbidden;
b. News regarding firearms and explosives
c. Contraband goods, stimulants, slander the Communist Party or the Motherland;
d. Sensitive information that should not be disseminated online;
e. Other unhealthy online information.

2. Increase oversight, 24 hours control of website content. Especially forums created by users. These must be strictly monitored, or else they should be edited or even taken down.

3. Websites that have not registered must immediately go to the Ministry of Information Industry to register your site. Registration is at: http://www.miibeian.gov.cn. We sincerely wish for your cooperation, proactively monitor your sites and make a contribution to China's century-long Olympic dream! Thank you for your support, we will continue to do everything we can to improve our service.
http://news.boxun.com/news/gb/china/2008/07/200807222211.shtml