Rokui was the Ikai for Jigenin (a lower rank of ancient Japanese nobility), which was demarcated from the nobles (Tsuki [intermediate ranking nobles]) with Goi (Fifth Rank) or higher, and was not allowed to enter the Imperial Palace.
地下人の位階とされ、五位以上の貴族（通貴）とは一線を画する位階であり昇殿は許されなかった。