The imperial rescript required a consensus among the emperor and all the Court nobles, and because of its complex procedure, it was used only on the ritual events such as accession and kaigen (changing the name of an era).
詔書は天皇と公卿全員の意見の一致が必要であり、手続きが煩雑なため、即位、改元など儀式的な事項にのみ用いられるようになった。