The class of Aritomo YAMAGATA and Hirobumi ITO of the Choshu Domain is given as ashigaru in historical sources because the term special chugen would have been likely to be misleading and easily mixed up with widely and generally known chugen.
長州藩の山縣有朋や伊藤博文が資料などの記述で、足軽扱いされるのは本来の広く一般的に知られる中間と紛らわしいためであろう。