禪門之職位，擬於朝廷之兩階，分東序西序之兩班。見兩序條。
西班 The western group, i.e. teaching monks stood on the west of the abbot, while those engaged in practical affairs stood on the east; this was in imitation of the Court practice in regard to civil and military officials.
一西序 於禪林之佛殿、法堂舉行佛事時，僧眾分右（東）側、左（西）側，兩班序列；西序指序列於西班之僧。東序選精通世事者擔任，稱知事；西序選學德兼修者擔任，稱頭首。依敕修百丈清規卷上載，西序計有首座、書記、藏主、知客、知浴、知殿等六頭首。又依黃檗清規，則有首座、西堂、後堂、堂主、書記、知藏、知客、知浴、丈侍、監收等。（參閱「兩序」3867）p3231