As a Migyosho was a notice or emergency order, its status as a document was inferior to a Kudashibumi (a document issued by a superior or office), which was an official document and effective indefinitely as a court ruling, license proof, etc.
下文が訴訟の判決、裁許状など効力が永久的になる正式文書であるのに対し、御教書は通達や緊急の命令などで、文書としての格は劣るものとされた。