It is said that the fact that any of "Shoku Nihongi," "Nihonkoki" (Later Chronicle of Japan), and "Shoku Nihon Koki" (Later Chronicle of Japan Continued) does not have the character for 'sho' in the title, supports this theory.
『日本書紀』に続いて編纂された『続日本紀』『日本後紀』『続日本後紀』がいずれも書名に「書」の文字を持たないこともこの説を支持していると言われる。