Yingyang ren is most commonly used to describe intersex individuals, although an individual does not need to be intersex to identify as yinyang ren. At times Yinyang ren can be used as a slur in China,  however, like queer, this term is reclaimed by some.
This category of gender identity and gender role is used in Chinese society to describe some individuals whose personalities and behaviors appear to be intermediate between masculine and feminine cases. Other characteristics may include assertiveness, aesthetic sensitivity, as well as lack of strong discrimination on their sexual orientation on the basis of their identity.
The flag was designed by an anonymous through Tumblr user Pride-Flags on January 29, 2017. The red background comes from a novel known as The Dream of the Red Chamber, which is a very culturally important novel in China whose protagonist is a yinyang ren. The black and white stands for yin and yang, as well as balance.
Yin is for femininity, yang is for masculinity, and ren is for person.