《后汉书·列传·桓荣丁鸿列传》
丁鸿与司空刘方上言： 凡按人口作标准的，应有阶品，蛮夷错杂，不得列入数内。
鸿与司空刘方上言： 凡口率之科，宜有阶品，蛮夷错杂，不得为数。
Ding Hong and the minister of works, Liu Fang, reported as follows: In all cases where population is taken as the criterion, there should be gradations in rank, and barbarians living in scattered fashion should not be included in the count.