"Chunagon" (vice-councilor of state) is a post ranking below Dainagon (chief councilor of state) in the Daijokan (Grand Council of State), the highest organ in the Imperial Court, and is Ryoge no kan (class outside of the Ritsuryo system), corresponding to Suke (assistant director) in the Shitokan (four classifications of bureaucrats' ranks).
中納言（ちゅうなごん）は、朝廷組織の最高機関、太政官の職の一つで、大納言に次ぐ官位で、四等官の中の次官（すけ）に相当する令外官。