The "Public Pledge on Self-discipline for China Internet Industry" has attracted more than 300 signatories since its launch March 16, said a spokeswoman for the Internet Society of China, who identified herself only as Miss Sun.

	See also:
•	A Human Rights Site? In China?
•	China Sweet, Sour on Spam
•	Group: Free Vietnam's Web Critics
•	Everybody's got issues in Politics

The pledge's main aims appear fairly benign: promotion of Internet use, prevention of cyber crime, fostering healthy industry competition and avoiding intellectual property violations.

Other clauses, though, seem less innocent, given China's tight control over information and the government's extreme sensitivity to criticism or political challenges. New regulations on Internet publishing take affect Aug. 1 "to promote the healthy development of Internet publications," the official Beijing Morning Post reported Monday.

Those who sign the pledge must refrain from "producing, posting or disseminating pernicious information that may jeopardize state security and disrupt social stability." The prohibition also covers information that breaks laws and spreads "superstition and obscenity." Members must remove material deemed offensive or face expulsion from the group.

Signers also pledge to monitor content of foreign-based websites and block those containing unspecified harmful information.

The pledge conforms closely to government policies making Internet service providers responsible for content posted on websites they host. It's a strategy to give the Internet enough room to blossom while keeping operators on notice not to push the envelope politically.

China has aggressively promoted the Internet for commercial purposes. As of April, China had more than 38 million Internet users and nearly 280,000 websites, according to the official Xinhua News Agency.

Yet the Communist Party is determined to curtail the Web's role as a forum of free discussion and source of information not available in the entirely government-controlled media.

A special police force monitors websites and sifts e-mail, searching for messages promoting causes such as greater political openness, the banned Falun Gong spiritual movement and independence for minority regions. Websites of human rights groups and Western and Taiwanese media are frequently blocked.

Internet cafes are required to track sites their users visit and report attempts to open those deemed subversive. Long prison sentences have been given to people accused of reproducing or forwarding information from such sites.

"They're trying to have it both ways. It's a difficult game to play, but they seem to be doing a not inconsiderable job of it," said Jack Balkin, a Yale University law professor who studies the Internet.

China has also closed thousands of Internet cafes since a fire June 16 at a cafe in Beijing that killed 25 people.

The Beijing-based Internet Society of China describes itself as a private, national self-governing body for the Chinese Internet sector. Its 140 members drawn from private companies, schools and research institutes, according to the society's website.

A spokesman for Yahoo's China office in Beijing confirmed the company had signed the pledge but refused to comment further. Yahoo's public relations agency in the United States, where the company cultivates an image of freedom and anarchic creativity, responded to an e-mail seeking comment by saying no spokesman was available.

Other portals the society listed as having signed the pledge include the popular Chinese websites Sina.com and Sohu.com, as well as Peking and Tsinghua universities, online media and technology companies, and government offices.