Jogan-shiki Code (貞観式)

Jogan-shiki Code was a Kyakushiki code (amendments and enforcement regulations of the Ritsuryo Code) that was compiled and enforced in the early Heian period. It consists of 20 volumes in total.

In the Jogan era, the times of Emperor Seiwa, it was compilated by eight members: FUJIWARA no Ujimune, MINABUCHI no Toshina, OE no Otondo, SUGAWARA no Koreyoshi, KI no Yasuo, OOKASUGA no Yasunaga, FURU no Michinaga, and YAMADA no Hiromune. Then on September 13, 871, the Jogan-shiki Code was submitted to the Emperor, and on December 7 the same year it went into effect as an Imperial Ordinance.

The Jogan-shiki Code was compiled from the existing "Konin-shiki Code" (the supplemental law determined in the Konin era), unifying corrected and supplemented rules and detailed regulations, and both codes were used together without abolishing the "Konin-shiki Code". Also, in case of revising articles of Konin-shiki, people were supposed to write''sakinoshiki (previous code)'' in the article, and after that ''Ima mazuruni (present idea)'' as the starting phrases and then write the content. Therefore, it took less time to compile, and the number of volumes were reduced to half of ''Koninshiki''. On the other hand, both the "Konin-shiki Code" and the "Jogan-shiki Code" had to be referred to. As a result, it became less practical, which would later make a reason to compile the fully-revised ''Engishiki Code (an ancient book for codes and procedures on national rites and prayers)'' and to abolish the "Konin-shiki Code" and the "Jogan-shiki Code".

Although some parts remain as quotes today, most parts have been scattered and lost.