Mido-ryu was the name of a style of Yusoku-kojitsu (knowledge of court rules, ceremony, decorum and records of the past) and manners for the descendants of FUJIWARA no Michinaga (Sessho [Regent] and Daijo-daijin [Grand Minister]) of Kujo line of Fujiwara-Hokke (the Northern House of the Fujiwara Clan) and the groups who assumed Michinaga as their ancestors.
御堂流（みどうりゅう）とは、藤原北家九条流藤原道長（摂政・太政大臣）の子孫の一門及び彼を祖とする有職故実及び作法の流派の呼称。