Beijing: China`s largest microblogging service, Weibo, has introduced a new code of conduct in a bid to restrict the type of messages that can be posted.
Weibo, which resembles Twitter, introduced new rules after local authorities complained that some `unfounded` rumors were posted by some users.
"This is a sign of the authorities trying to restrain the Internet in China, but a hardcore group of people will still find ways to get round the restraints," the BBC quoted Dr Kerry Brown, head of the Asia Programme at the Chatham House think tank, as saying.
According to community conventions, users will not be able to spread rumours, oppose the basic principles of China`s constitution, reveal national secrets, threaten China`s honour, and call for illegal protests or mass gatherings.
According to a report, a credit score system will be introduced with points deducted if rules are breached.
Users are reported to start with 80 points and gain more by taking part in promotional activities, but lose points if they break rules.
It is reported that if a subscriber`s points fall below 60, a low credit warning would appear on their microblog, leading to the possible cancellation of their account if it hit zero.
"There is a tradition of indirect criticism in which people make points using coded references. I very much doubt these rules will change anything," Brown said.
Chinese authorities have been critical of false reports spread through microblogs, including news of the assassination of North Korean leader Kim Jong-un, and stories of a military coup that tried to overthrow Chinese President Hu Jintao.
Chinese social media has also been pressured to filter posts featuring words associated with controversial events.