There was a record in Taiho Koryo (Taiho code for households) and Taiho Kaniryo (Taiho code for government officials) that a Borei (chief of the four districts of the capital) was deployed in every four Bo(s) in both of Sakyo and Ukyo.
左右京とも四坊ごとに一人の坊令（ぼうれい）を置き合わせて12人の坊令を置いたことが、大宝戸令（こりょう）と大宝官員令（かんいんりょう）にみえる。