《元史·本纪·卷二十七》
七品以上官员中，有宏伟规划长远策略可以济世安民的，据实封书上奏。
七品以上官，有伟画长策可以济世安民者，实封上之。
Among officials of Rank 7 and above, those who have grand plans and long-term strategies that can help the world and protect the people shall submit a confidential letter to the emperor.