The shrines whose names appear in the Six Official Histories (ritsukokushi), namely the Nihon shoki, Shoku nihongi, Nihon kōki, Shoku nihon kōki, Montoku jitsuroku, and Sandai jitsuroku, are the kokushi genzaisha. Such shrines are also called kokushi shozaisha, "shrines that appear in the Official Histories." There is some overlap between the shrines listed in the Official Histories and the shikinaisha, the shrines listed in the Jinmyōchō (Register of Deities) in the Engishiki. However, the term kokushi genzaisha usually refers to shrines found in the Official Histories but not in the shikinaisha. Along with the shikinaisha, the kokushi genzaisha are regarded as historically important ancient shrines.