BEIJING — Chen Yulu never thought her home province of Hunan had any culture that she would be proud of, much less become an ambassador of.

But these days, the 23-year-old is a self-proclaimed ambassador of nüshu, a script once known only to a small number of women in the south China.

It started as a writing practiced in secrecy by women who were barred from formal education in Chinese. Now, young people like Chen are spreading nüshu beyond the women's quarters of houses in Hunan's rural Jiangyong, the county whose distinct dialect serves as the script's verbal component.

Today, nüshu can be found in independent bookstores across the country, subway ads, craft fair booths, tattoos, art and even everyday items like hair clips.

Nüshu was created by women from a small village in Jiangyong, in the southern province where Mao Zedong was born, but there's little consensus on when it originated. Scholars estimate the script is at least several centuries old, from when reading and writing were deemed male-only activities. So the women developed their own script to communicate with each other.

The script is slight with gently curving characters, written with a diagonal slant that takes up much less space than boxy modern Chinese with its harsh angles.

"You won't allow me to go to school. Okay, I get it. So what's my way out? I'll find ways to educate myself," said Xu Yan, 55, the author of a textbook on nüshu.

Women lived under the control of either their parents or their husband, using nüshu, sometimes called "script of tears," in secret to record their sorrows: unhappy marriages, family conflicts, and longing for sisters and daughters who married and could not return in the restrictive society.

Xu is also the founder of Third Day Letter, a nüshu studio in Beijing named after a centuries-old practice by the script's practitioners. The third-day letter is a hand-sewn book presented in farewell to a woman in Jiangyong on the third day after her marriage, when she's allowed to visit the childhood home she left.

The script became a unique vehicle for composing stories about women's lives, typically in the form of seven-character line poems that are sung. A secret world sprung form the script that gave Jiangyong women a voice through which they found friends and solace.

That secret world still resonates today as a source of strength for young women dissatisfied with patriarchal constraints.

Chen, who studied photography at an art school in Shanghai, said her male professors often doubted that she could keep up with the male photographers because of her slight physique. That attitude, she said, is "in every aspect of life, there's nowhere it doesn't touch."

She was frustrated but didn't see much room to push back — until she learned about nüshu.

"I felt that I had received a very strong power, and I think a lot of women need this power," she said.

Chen wanted to make a documentary about feminism and came across nüshu in her online search. When she realized the script originated from Jiangyong, just a few hours from her hometown, she immediately knew that she had found her graduation project's topic.