Circular medal - Kaisho

...Generally, it is a document that conveys the same matter by circulating it to multiple recipients in turn. It is also called a circular letter or a circular letter. In the Middle Ages, this type of document was often used when ordering attendance at various government offices or the appearance of parties in lawsuits. In the early modern period, circular letters were used when feudal lords or magistrates conveyed orders to villages under their control, for daily communication between villages, or for documents calling for participation in uprisings (ikki circular letters), but in the early modern period, the term "circular letter" usually refers to the former.

*Some of the terminology explanations that refer to "kaisho" are listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…一般的には，複数のあて先に対し，順次に回覧させる方法をもって同一の用件を伝達する文書のこと。廻文，廻章とも言い，中世には，諸役への参勤や訴訟当事者の出頭を令する際に，この形式の文書が多く用いられた。近世では，領主や代官が支配下の村々に命令を伝える場合や，村々の日常的な連絡あるいは一揆への参加を呼びかける文書(一揆廻状)に，廻状が使用されたが，ふつう近世で廻状と言えば，前者を指す。…

※「廻章」について言及している用語解説の一部を掲載しています。

出典｜株式会社平凡社世界大百科事典 第２版について | 情報