According to legend, Huang E, the wife of Ming Dynasty poet Yang Shen, was also a poet. Yang Shen was demoted and banished to the border. Huang E missed her husband and wanted to write a love letter, but was afraid that she would suffer misfortune because of the letter. Entrust a white handkerchief to be delivered to your husband. Yang Shen received the plain silk, thought about it over and over, and finally realized that his wife used a square silk handkerchief to express her inextricable lovesickness, so he wrote the poem "Supa":
If you don't write love words, you can't do it. Write poetry,
A square Supa expresses lovesickness.
Lang Jun turned over it carefully and looked at it.
There were silk threads horizontally and vertically.