However, there are no definite rules about it in the Yoro Code and so on; it is only mentioned in Zhu Theory (notes which is said to be written by Judicial Officials) in the external ordinance of Rokuryo in "Ryonoshuge" (Commentaries on the Civil Statutes).
ただし、養老令などに直接規定したものは無く、『令集解』の禄令令条外条における朱説（明法家による注釈とされる注記）に示されているに過ぎない。