gǔ / rén / cháng / yòng / bó / zhòng / shū / jì / lái / biǎo / shì / xiōng / dì / zhī / jiān / de / zhǎng / yòu / cì / xù

古人常用伯仲叔季来表示兄弟之间的长幼次序。

In ancient times, people often used bózhòngshūjì to indicate the order of seniority among brothers.