The term, `kori' (郡) was used after the establishment of Taiho Ritsuryo (Taiho Code), and documents (mokukan [narrow, long, and thin pieces of wood strung together that were used to write on in ancient times]) which contained `kori' (評) discovered before that..
「郡」と言う用語が用いられるのは、大宝律令制定以降であり、それ以前は「評（こおり）」を使っていた文書（木簡類）が見つかっている。