Do not make irresponsible remarks

不要乱说话 (bú yào luàn shuōhuà): do not make irresponsible remarks

Teacher gagged with banners reading “refrain from doing things that are not to be done” and “refrain from remarking on things which ought not to be remarked upon.” (Southern Metropolis Daily)

On August 10, 2010, the education bureau of Pizhou City, Jiangxi Province issued an official document to all secondary and private schools. After stating that three Pizhou teachers had recently been detained for spreading rumors online, it instructed all teachers to

...pay attention to their images, be mindful of politics, speak about the big picture, refrain from doing things that are not to be done, and from irresponsibly remarking on things which ought not be remarked upon.

要注意形象,讲政治,讲大局,不该做的事不要做、不该说的话不乱说。

Campaigns against online rumors have become common in China. In the summer of 2013 central authorities launched a massive anti-rumor campaign—complete with a legal interpretation sanctioning prison time and fines for digital rumor-mongers—in which many influential microbloggers were targeted.