The word 'Fukai-no-Joten/ Fukaijoten' is not the name of the code itself, but the word extracted by present scholars from a part of a long adjective phrase qualifying a certain code whose name is not mentioned, as follows: '[the code] that His majesty Oyamatoneko no Sumera Mikoto (referring to an emperor), who resides in the highly respectable and noble Omi-no-Otsu-no-Miya Palace, established as the irreversible and eternal code, which should not be modified as long as the universe exists and as eternal as the sun and the moon shed light.'
また、法の名称そのものではなく、何か名前が出てこない法の形容部分である「かけまくもかしこき近江の大津の宮にあめのしたしらしめし大倭根子天皇の天地とともに長く日月とともに遠く改めるまじき常の典と立てたまひ敷きたまへる」というような長い形容の中から、現代の学者が一部を抜き出して使う語が「不改常典」である。