Ryo (administrative code) assigned Chugu-shiki (Office of the Consort's Household) to manage the Grand empress dowager's affairs, quoting Ryo no gige (commentary on the Ryo) as its legal basis which says that 'the Grand empress dowager is Chugu (Empress) accordingly', but, in fact, Taikotaigogu-shiki (Office of the grand empress dowager) was established to serve Grand empress dowager exclusively.
令では中宮職を担当の役所となし、『令義解』では「太皇太后……の宮また自ずから中宮なり」とし、中宮職をもって太皇太后に仕える根拠とするが、実際には中宮職と別個に太皇太后宮職をおいて奉仕させた。