The generation name is written in one character and is usually years or centuries ago dictated in a generation poem (banci lian 班次聯 or paizi ge 派字歌 in Chinese). Each of the poem's characters is to be a generation name. After the last character of the poem is reached, the poem may be extended, or (more usually) the generation cycle is reset and the first character is reused. The poem varies in length from two dozen characters to a hundred characters.
The common generation character may be either the first (more common) or second one of the two-character name, but it is in the same position for everyone who shares it. For some families, the position switches from generation to generation, so that one generation will share the same first character in the given name, while the next will share the same second character.