Chinese authorities have tried over the years to ban all sorts of behaviours on the grounds that they are "uncivilised." They've attempted to stop public spitting. They've tried to stop people from slurping their soup too loudly. They've had a go at prohibiting people from jaywalking and cutting in line.
Now, another staple of Chinese life is facing an existential crisis: The sartorial practice known - not always affectionately - as the "Beijing bikini," although it is certainly not confined to the capital.
It is a sure sign that summer has arrived in China when men start rolling up their shirts, ideally resting them on the natural ledge of their beer belly.
The theory, based in traditional Chinese medicine, is that exposing one's midriff helps air out the warm "chi" energy around the internal organs. So in parks and on street corners, on motorbikes and at open restaurants, men think nothing of pulling up their shirts and letting it all hang out.
But now authorities in cities around the country have declared that the broader practice of exposing body parts that should be covered - including chests, bellies and feet - is unseemly.
Jinan, a city between Beijing and Shanghai, is the latest municipality to try to crack down on "casual exposure," particularly among "bang ye," or "exposing grandfathers."
People there now face punishment if they are "not dressed properly in public, especially in parks, squares, communities, buses, scenic spots, commercial blocks and other areas that are densely populated."
Being shirtless and taking off shoes to air the feet is the worst crime, according to the Jinan local government, which has called on city departments, the news media and grass roots organizations to play a role in ensuring decorum is not breached.
One reporter for the Jinan Daily took the order to heart and found many men who were "shirtless or exposing their bellies" in parks and squares. "They may feel it's not a problem being shirtless to enjoy some cool, but they don't know it's disrespectful," the report concluded. "In public, don't lose your civilized image."
Those caught exposing their midsections will be given a verbal warning.
"Penalties are not the ultimate purpose," a Jinan official said, according to the Beijing Youth daily. "We just want people to pay more attention to these kinds of antisocial behaviors."
But Tianjin, a port city outside Beijing, is imposing fines of up to $30 on offenders. The northeastern city of Shenyang has also imposed similar regulations.
Many commenters on Weibo, China's answer to Twitter, supported the various governments' efforts. The most popular response was the one that recommended promoting this effort nationwide.
Another supporter said: "I can't stand it. They make public places their own home. It's as if they are taking the sky as their quilt and the earth their bed."
But others decried the efforts as irrelevant or discriminatory. "There's nothing wrong with being shirtless. Our ancestors from generations back did this," said one. "The government should pay more attention to improving people's well-being."
The People's Daily, the mouthpiece of the Communist Party of China, has started posting about the efforts to make people cover up. One post noted that many places are taking measures to curb this casual exposure, showing shirtless men and a woman in a park who had taken her stockinged feet out of her shoes.
A second Weibo post asked people what uncivilized public behavior they hate the most. The most common complaints included smoking and spitting in public places.
In the capital, some practitioners of the letting-the-warm-energy-escape theory scoffed at the idea of banning Beijing bikinis.
"It's not a big deal. It's just our habit. We have to do this when it's hot," said a man who gave only his surname, Fu. He was sitting in a deck chair outside his building supplies store in a Beijing alley as the mercury hit 100 degrees, his blue shirt entirely open.
"We are shirtless because we need to cool down," he said, while his wife yelled from inside the store: "It's not civilized."
As a man came down the alley with his T-shirt slung over his shoulder, Fu yelled out: "Put your clothes on!" as if to protect him from inquisitive reporters.
Across the road, a group of men were gathered on a shady street corner, one of them sitting on an overturned bike, playing cards and listening to a radio. Some were fully dressed. Some had their trousers rolled up. But the majority were sporting Beijing bikinis.
"I'm not shirtless. I'm even wearing shoes," said one man happily airing out a belly that had consumed many bottles of beer and bowls of noodles. Another pointed to his navel and said to peals of laughter: "The warm air can go out through the hole."
When a woman in a midriff-baring singlet top and cutoff shorts walked by, the men complained that any new rules should apply to everyone equally. The reporters duly took up the men's dare and asked the woman about covering up.
"I support this very much because they should respect other people," Lily Huang, a dancing instructor, said after reading the reports from Jinan, noting that it applied not just to midriffs but to all unseemly nakedness.
"In an outdoor environment, they should not be naked on top and walking around in public," she said, making a strong distinction between her level of exposure and theirs.
The men were not to be swayed. "It's a personal style," said one. "If women reveal their belly it's beautiful, but when we do it, it's ugly?"