Chinese internet users wanting to vent frustration at their government are using a coded language to dodge censorship filters.

According to an unofficial lexicon of online political slang, there are at least 25 phrases in China secretly loaded with taboo meaning.

For example, saying that someone is “checking the water meter” means that police are knocking at the door. The term playing “hide-and-seek” is used to discuss dying in police custody, after authorities once cited the game as the reason that a prisoner had died.

Neighbouring North Korea’s rotund leader, Kim Jong-un, has become “Kim Fatty III” online – though many Chinese bloggers also make a serious point by referring to their own country as “West Korea” because of its draconian laws.

According to Perry Link and Xiao Qiang, the authors of Decoding the Chinese internet: A glossary of political slang, the terms are rife among the 198 million users of Weibo, China’s version of Twitter.

It is not only politicians who get a ribbing with the phrases, but their sycophantic supporters too. A “volunteer 50-center” refers to an online commentator who defends the Chinese government for free, rather than being recruited for the job at the alleged 50 cent per post rate.

Charlie Smith, co-founder of the internet transparency group GreatFire.org, said it was a constant “game of cat and mouse” between authorities and surfers battling the “great firewall of China”.

“I think that it shows that there is growing dissatisfaction with internet censorship,” said Mr Smith. “The Chinese authorities have set a pretty large task for themselves. It is hard to keep on top of this kind of subversion.”

The target of another joke is the government’s attempts to delete user accounts, with the web community laughing about “reincarnations” under new names. Political cartoonist Kuang Biao is reportedly on his 47th Weibo account.