This document is a postscript written by King Jeongjo (r. 1776-1800) in 1794 after reading the letters that one of his predecessors, King Seonjo (r. 1567-1608), had written to an official named Song Eon-sin. In the postscript, the king provided a brief explanation of the letters and praised the mutual trust and respect between his ancestral monarch and the minister. King Jeongjo’s postscript is highly regarded not only for its historic significance but also for its literary and artistic merits.