As the editor, MIYOSHI no Tameyasu himself stated that he had collected 'hogo' (scraps of paper), the book, including many historical materials especially in the end of Heian period when he lived, makes itself a valuable collection of monjo that reports realities of government according to the Ritsuryo code from the middle to the end of the Heian period.
また編者三善為康が身近な「反故」を集めたと自ら述べているように、編者が生きた平安時代末期の史料が特に多く収録されていることから、平安時代中紀以降末期にかけての律令政治の実態を伝える貴重な文書集となっている。