Originally, Shosho (imperial edict, decree) and Chokushi (imperial order) existed as orders issued by the emperor as specified in the Ritsuryo codes, but, by reason that the issuing of such orders was limited to those cases of important issues, and the format was regulated strictly, the issuance was allowed only at special occasions.
本来、律令に規定されている天皇発給の命令書としては、詔書・勅旨があったが、これらの発給は重要な案件の場合に限定されており、また形式が厳密に定められており、特定の機会にしか発給ができなかった。