This is an admonitory letter written by Yi Wonik for his offspring in 1589 (32nd year of King Seonjo’s reign). He particularly asks his dependents not to bury him in other regions sticking to the theory of geomancy, but to entomb him in his family grave mountain. In addition he admonishes them not to gather wealth by dishonest means or without benevolence. This letter shows his attitude toward the life, and suggests that his way of thinking is logical.

This letter was written by Yi Wonik to his grandson, Suyak, who was appointed to the magistrate of Yeonpung in 1628 (sixth year of King Injo's reign). In this letter, Yi Wonik presented eight items of virtue which should be kept in mind when ruling over a region. These items seems to have been based on his own experience which was acquired during his outstanding services as a local civil official including a dosa ("administrative official") of Hwanghae-do, the magistrate of Anju, and the gamsa ("governor") of Pyeongyang. This letter is a valuable material, which not only shows his deep concern about his grandson, but also evinces his attitude as a governor.

This poem was written by Yi Wonik to express his regret over the death of his wife in 1604 (37th year of King Seonjo’s reign). This seems to have been used as a streamer during the funeral. It seems that this streamer was not burnt after the funeral as usual but has been handed down in the jongga ("head family") with much care since this was written personally by Yi Wonik. It is assumed that he might be seized with a great pity for his wife much more since she died in 1604 when he was honored as Hoseonggongsin, a meritorious retainer, in recognition of his service during the Japanese Invasion of Joseon.

This testament was written by Yi Wonik, and left to his son, Yi Uijeong, and other descendants in 1630 (eighth year of King Injo’s reign). This is largely composed of six items as follow: first, the funeral must be simple; second, the tradition must be observed that a hut is built near a grave and the grave is taken care of for three years; third, shamanistic or Buddhist rituals are not allowed in the house; fourth, the theory of geomancy is not trustworthy; fifth, things offered in the memorial service must not be extravagant; and sixth, the memorial service for Iknyeonggun must follow the suggested principles. This is a valuable material for understanding the memorial service and the funeral ceremony of a sadaebu ("noble class of Joseon") family in the 17th century.