The humble midriff top — an item of clothing that exposes a person's lower belly and back — has been a staple of Western fashion for decades.

Key points: The Chinese city of Jinan has issued an order to stop men exposing their midriffs

The Chinese city of Jinan has issued an order to stop men exposing their midriffs This practice, designed to cool men during heat, is known as the 'Beijing bikini'

This practice, designed to cool men during heat, is known as the 'Beijing bikini' Punishment for donning the bikini will involve verbal warnings and public shaming

It regularly cameos on the catwalk, in music videos, and on streets in sweltering cities around the globe — there's even been a song written about it.

China is no stranger to this garment as its steamy climate has created an idiosyncratic offshoot, known as 'Beijing bikini', where older men roll their tops up and expose their midriff in a bid to keep cool.

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In the eastern city of Jinan, the Beijing bikini has become such an unwelcome sight for local authorities that they've begun to target the practice.

They have recently issued a directive against the practice, labelling it "uncivilised behaviour".

The authorities specifically called out the city's bikini-toting older men, referred to as bang ye, who they accuse of tarnishing the city's image.

In a recent interview with Beijing Youth Daily, a spokesperson for the city's civility department told the paper that the Beijing bikini affected "the image of the city and the perception and feeling of the public".

"Urban civilisation is related to everyone. We also hope that we can start from scratch and jointly maintain the image of the city," the spokesperson said.

But they added that the behaviour had significantly decreased in recent years.

The West thought the bikini was controversial too

French actor Brigitte Bardot was one of the most prominent celebrities to don the bikini after its creation. ( Wikimedia Commons )

The Western bikini's origins date back to 1946, where French designer Louis Réard debuted the bikini — a women's swimsuit consisting of small triangular pieces of fabric which covered breasts, buttocks and genitalia.

It caused an incredible stir at the time of its launch, as women were arrested for publicly baring skin at beaches and swimming pools in the years before its creation.

Many women, including Australian swimmer Annette Kellerman, fought against prevailing social conventions that bound women in impractical togs that once included full-length dresses and knitted wool suits.

Ms Kellerman fought for more practical swimming attire for women in the early 20th-century. ( Sears Studio: NPG )

The origins of the Beijing bikini however, remain unclear, though the sight of older men baring bellies in Chinese cities has been a common one — an exhibition was dedicated to them in 2015.

The pushback against their bellies within China has equally been common, with some citizens railing against what they see as a fashion faux pas.

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In 2002, the Beijing Youth Daily ran images of bare bellies in a bid to shame men out of the practice.

Shame will also feature in Jinan's efforts to curb the practice, where offending men will be given a verbal warning first, and will later be named and shamed by authorities if they do not comply.

The city's official guideline on the "rectification of uncivilised behaviour" noted that that local media, grassroots organisations, and other bodies were obliged to "vigorously supervise, expose and attack" the behaviour.

Many observers on Chinese social media noted that there was no law to ban shirtlessness.

And for one Weibo user, the latest development in bikini-policing is a step too far.

"The supervision in private areas reflects arrogance and idleness of power," the user wrote.

"Do not kidnap laws with moral matters, after all, China has not set up a moral court similar to Iran's."

Michael Li and Bang Xiao contributed to this report.