Besshufusensho is a law code containing Daijokanpu (official documents from Daijokan to local governments) and imperial decrees issued between 902 and 971
This old possession of the Hiromhashi family (Old possession of The Toyo Bunko Iwasaki Bunko) is the only denpon (existent manuscript) and a dead leaves book that lacks the cover, etc. Therefore, the titles and okugaki (postscript) are not missing and the original title is unknown. It used to be titled "Fusensho, separate volume", but this title was added by Katsumi Kuroita, the editor of Shintei Zouho Kokushi Taikeibon (a newly revised and enlarged edition of the Anthology of Japanese History). The editor and the year of establishment are unknown due to the circumstances of the transmission of this book and insufficient historical information. However, it is said that it was established before 1029.
Since it was titled as "Fusensho Separate volume", it can also be considered to be related to "Ruiju fusensho", for example, a separate book of "Ruiju fusensho". But, it is believed to be edited originally since some Daijokanpu and imperial decrees are not included in "Ruiju fusensho". The compilation has a style in which each documents are divided by the same category as "Ruiju sandai kaku (assorted regulations from Three Reigns)" or "Ruiju fusensho". However, since there are some incomplete parts in the classification, it is believed to have been left incomplete.