In the Tang Dynasty, some ministers were lazy. When signing official documents, they omitted their surnames and only wrote their first names to show that they had read them. This method quickly became popular. When Wang Anshi was prime minister, he had to contact a lot of official documents every day. After each copy was processed, he wrote a word "stone" on it. Wang Anshi's handwriting is scrawled, and the "mouth" in The Story of the Stone is often drawn as a circle. Later, in order to save trouble, he simply drew a circle when signing. Other officials have followed suit. "Circle reading" gradually spread.