 He is perhaps best known for having written the postscript of the "Hunmin Jeongeum Haerye", the commentary on and explanation of the native alphabet Hangeul invented by King Sejong in 1443.He also contributed to the "Goryeo-sa", the official history of Goryeo dynasty, and the "Yongbi Eocheon-ga" (용비어천가).His second son, Jeong Hyeon-jo, was married to Princess Uisuk, the second daughter of King Sejo of Joseon.