In Liu Gu Yan Qiu Kai Fa Su Lan, Liu Gongquan and Yan Zhenqing are both good at calligraphy. Han and Su: Han Yu and Su Shi are both good writers and are often used to praise a person's good handwriting.
Liu Gu Yan Jin, a China idiom, means that Liu Tang Gongquan calligraphy has strong bones and tight structure; Yan Zhenqing's calligraphy is dignified and magnificent.