The ground lies in a description in "Shoyu mokuroku" (the contents of "Shoyuki" [The Diary of FUJIWARA no Sanesuke]) that reads: 'December 17, 1002, I have finished a category of seji yoryaku (examples of social affairs),' in the book having been handed down to the Ononomiya family from generation to generation, and so on.
その根拠は、『小記目録』（『小右記』の目録）に「長保四年十一月五日、世事要略部類畢んぬ事」と記されていることや、本書が代々小野宮家に相伝されていたこと等である。