Since the time when the study of Japanese classical literatures started in the Edo period, it has been highly evaluated as a document where information about vocabulary and about pronunciations of words is available, and in addition, it has also been highly evaluated in the fields of Japanese literatures, of Japanese language study and of Japanese history, as a document in which information about states of society, customs and social systems is available.
江戸時代の国学発生以降、平安時代以前の語彙・語音を知る資料として、また社会・風俗・制度などを知る史料として国文学・日本語学・日本史の世界で重要視されている書物である。