Go(ai) number - Aiban

...Working according to the rank system is called "duty," working on it is called "upper rank" or "inner rank," and the ranks are called "banbun" or "bancho," and the leader of an organized rank is called "bancho," "banto," or "tounin." Members of the same rank are called "goban" or "aiban," and feelings of mutual assistance and solidarity are often seen in these.
[Ancient nations and the number system]
Since the 6th century, the Yamato region has had numerous technical departments, such as the Horsekeeping Department, the Talent Department, the Blacksmith Department, the Mud Department, the History Department, and the Storehouse Department.

*Some of the terminology explanations that refer to "Go (phase) number" are listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…番制度による勤務に当たることを〈当番〉，これを勤めることを〈上番〉〈勤番〉などといい，その結番交名（きようみよう）を〈番文〉〈番帳〉，編成された一つの番の統率者を〈番長〉〈番頭（ばんがしら∥ばんとう）〉あるいは〈頭人（とうにん）〉などと呼ぶ。同一の番所属者は〈合番〉〈相番〉と呼ばれ，そこにはしばしば相互扶助，連帯の感情が認められる。
［古代国家と番制度］
　大和国家では6世紀以来，馬飼部，才伎（てひと）部，鍛冶部，泥部，史部，蔵部などの技術系の品部が数多く設置される。…

※「合（相）番」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