SHANGHAI -- China’s biggest digital entertainment and gaming expo has announced tough fines for models whose costumes reveal too much flesh, in the latest sign of the impact of the Chinese government’s recent campaign for stricter morality.

ChinaJoy, a huge trade fair that also features conventions for fans of manga and cosplay, has become famous since its debut in 2002 for the hordes of (mainly female) models dressed as characters from Japanese anime stories, often in very skimpy costumes, to promote online gaming and other digital entertainment. The event, held in Shanghai every July, has been described as an “exhibition of flesh” and a “fantasy fetish sex expo.”

This year, though, the company hired by ChinaJoy’s organizers to vet agencies supplying models and performers says it will be applying new rules. A spokeswoman for New Silk Road Fashion told Shanghai website the Paper that agencies whose models violate these rules will be fined. The fines will start at 5,000 yuan (around $800) for models who wear only bikinis, or whose tops reveal more than 2 centimeters (three-quarters of an inch) of cleavage. If their trousers or skirts reveal their hip bones, or begin more than 2 two centimeters below their navels, they will face a similar punishment. Other banned items included miniskirts that reveal buttocks or transparent clothes through which underwear is visible, while anyone not wearing underwear at all will be fined 5,000 yuan.

Male models who appear topless, wear only underpants or reveal their hip bones will have to pay the same amount, the Paper reported. The stiffest punishments, however, are reserved for anyone taking part in pole dancing or cage dancing -- and for models who “assumed vulgar poses” or become “overintimate” while posing for photographs with members of the public. Such infractions will incur a fine of 10,000 yuan (around $1,600).

The spokeswoman told the Paper that the rules were designed to ensure the “smooth and positive” running of the event. However, the fact that the regulations were leaked online before they were officially reported suggests that, as one Shanghai website put it, they have “caused serious concern in the local nerd community.”

In previous years fines did not appear to have been a particularly effective deterrent. In 2012, for example, the Global Times newspaper reported that a number of modeling agencies had been fined for violating the event’s dress code, yet it said the “phenomenon of scantily dressed models has remained a stubborn problem.”

However, this year’s rules, and the attempt to enforce them, appear to be the strictest yet. They follow the first ever ban on glamor models at the Auto Shanghai car show, held in April. The ban did not prevent car companies hiring young women in figure-hugging costumes as “sales representatives,” but it did lead to a street protest by a group of professional car show models who complained that their livelihoods were being taken away from them.

Some commentators, however, have said the appearance of scantily clad models at such events is demeaning to women, reinforces sexist attitudes in Chinese society and should be "cleaned up." And with the leadership of President Xi Jinping currently in the midst of a major campaign against corruption, excess and what are seen as over-liberal Western values, some observers believe the new rules may have more impact this year.

The authorities recently insisted that one Chinese TV drama series be re-edited because the female characters’ costumes revealed too much cleavage. However, at least one male Internet user saw a silver lining in the new expo rules – he offered to take measurements to check for infringements of the regulations himself, according to local magazine That’s Shanghai.

And the need to introduce such rules is also a reminder of how far mainstream morality has changed in China, at least among some members of the younger generation. China officially bans all forms of pornography, for example -- yet a Japanese adult video star, Sora Aoi, became one of the biggest celebrities on Chinese social media in what one local news magazine has described as an example of “safe rebellion” by the young generation. A number of Chinese companies have hired Japanese porn stars to appear at their functions and public events, though the government has reportedly recently tried to crack down on such appearances. (The authorities last year also launched a high-profile campaign against prostitution in the southern city of Dongguan, although recent reports suggest this has had only a minor impact on the sex trade in China.)

The official website of the ChinaJoy gaming expo itself, meanwhile, suggests that a rebellious spirit is a part of the event’s identity. It says that in the early years of the development of digital entertainment and gaming in China, such games were “unjustly ... killed by the traditional media, criticized by experts and professors, and tabooed and boycotted by parents and teachers alike.” Now, however, it says they have become an “irresistible current,” providing “entertainments for the masses.” It adds that revenue from China’s gaming industry reached 114.8 billion yuan (18.5 billion dollars) last year, and is growing.