The Cyberspace Administration of China (CAC) on Wednesday issued a regulation banning the use of malicious contents in netizens' account usernames, avatars, and personal introductions across all Internet services.

The 10-clause CAC regulation stipulates that avatars and account handles should not include information that violates the Constitution or the country's laws, subverts State power, undermines national security and sovereignty, or is deemed to be rumor-mongering.

In the personal signatures of blogs, social media accounts such as Sina Weibo or other Internet services, one should not post "malicious content," which includes the promotion of cults and the dissemination of pornography or extremism among others, according to the regulation.

The regulation says that all avatars and account handles registered on blogs, microblogs, instant messaging services, online forums, comment sections as well as other services should be monitored.

Chinese Internet observers believe the new regulation is a part of the CAC's continuous efforts over the past two years to reorder the online expression system and strengthen Chinese people's sense of responsibility in cyberspace.

Xu Feng, the head of the CAC's mobile Internet bureau, emphasized that the regulation would not take away netizens' freedom to choose a personalized username. 

"We will adhere to the principle that people can have personalized usernames and provide real names when registering," he said at a press conference on Wednesday in Beijing.

In an earlier interview with the Global Times in late January, Xu said that the authorities have been encouraging ordinary people to provide tip-offs on illegal information online, one of the major means to supervise the Internet.

A document passed by Chinese lawmakers in December 2012 stated that Internet service providers should ask their users to provide proof of their identity.

The CAC has noticed the phenomenon of netizens using the names of officials and celebrities to defame or spread rumors, he said, adding that some usernames will indicate a sex business, gambling, terrorism or secessionist activities.

Some accounts use monikers such as "Arms merchant" or "Countryside casino."

Such account information has severely polluted cyberspace, and this kind of "freedom" should be regulated, Xu said.

Internet service providers should shoulder the main responsibility of regulating their users and they are the main target of the new regulation, according to Xu.

Before the regulation formally takes effect on March 1, Internet companies should prepare to inspect their users, assign employees to monitor accounts and encourage users to report harmful account handles.

Internet companies should take measures, including warnings and suspending or shutting down accounts if they are discovered to have violated the regulation, Xu said.

WeChat, an instant messaging app developed by Tencent with over 500 million users in China, said in an e-mailed reply to the Global Times on Wednesday that they have already enacted the new regulation, without elaborating further.

Tencent added that the company will work hard to keep the WeChat environment clean and healthy.

An anonymous source at the company told the Global Times that they always refuse registrations if people try to use the name of a Chinese State leader.

Sina Weibo, the largest microblog platform in China with more than 200 million registered users, Wednesday also said in a reply to Global Times that they have already cleaned up 293 harmful usernames, 90 avatars and 82 personal introductions, which are account handles related to politics, pornography and security issues.

Most of the 133 public accounts recently shut down on the social media app WeChat were reported by netizens, according to the administration. Those accounts are blamed for distorting the history of the country and the Communist Party of China, and illegal marketing.

Zhang Chenggang, head of the illegal and harmful information reporting center of the administration, told the Global Times that after spotting problematic posts, the center either asks the websites involved to delete them, or meet with website staff to talk about their problems. Later the center will regularly publish the names of the websites with serious problems.

The reporting center directly dealt with 1.09 million tip-offs in 2014.

About 100 news portals, search engines and forums are also required to supervise the information on their websites and to deal with tip-offs from their respective users. They dealt with some 250 million tip-offs in 2014.

The campaign to clean up cyberspace is in line with President Xi Jinping's remarks during the first meeting of the central Internet security and informatization leading group in February last year.

Xu told the Global Times at the conference that if netizens think Internet companies' measures are unreasonable, they can report directly to the CAC, which encourages netizens nationwide to provide tip-offs.