China's largest microblogging service has introduced new rules aimed at preventing the spread of online rumors and other content deemed inappropriate by Internet censors.

Sina Weibo, a Twitter-like service with 300 million users, has been under increasing government pressure in recent months to more aggressively censor its content.

It has rolled out a new set of guidelines that forbids posting material that is considered “untrue,” “harms national unity,” or “destroys societal stability,” among other things.

Under the new “user contract,” Weibo users will be given a base score of 80 points, which will be deducted for each violation. The user's account will be terminated when the balance reaches zero.

The system also punishes those who use code words, homonyms, or abbreviations in their online messages to attempt to bypass Internet censors.

Sina Weibo already employs a large “rumor control team” and recently pledged to work more with government censors to squash online rumors after it was punished for failing to adequately restrict false rumors of a political coup.

China's massive network of Internet censors – dubbed the Great Firewall of China – has been working overtime in recent months as the date for a once-in-a-decade leadership transition in the Communist Party draws closer.

Recent high-profile scandals involving suspended Politburo member Bo Xilai and blind dissident Chen Guangcheng have apparently prompted Beijing to impose even stricter controls on Chinese Internet users.

In March, Beijing introduced new rules requiring all of the country's microblog users to register using their own names, in an effort to better control what is being posted online. But many of the country's microblog services have struggled to enforce the rule.

Reports say that Sina Weibo is encouraging compliance with the real-name registration policy by offering users additional points if they reveal their personal identities. Users may also gain points by adhering to the censorship guidelines for a certain period of time.

Chinese microblog services have become wildly popular in recent years. Popular Western social media websites such as Facebook and Twitter are blocked in China.