In December 1806, a man named Kim Su-o passed away in Yesan, Chungcheong Province, where he had been famous for extreme filial piety. After his death, local Confucian scholars drafted and signed a recommendation letter to apply for a government prize for filial piety and practices. The initiative was led by Yi Heungsuk.The recommendation records the details of
how Kim Su-o had served his parents and contains at its end the hand-written names and signatures of all the people who recommended him. In the margin of the recommendation are the provincial governor's signature and comment that he would investigate the case before he reported it to the central government.