In some areas, or some individual shops, unaju does not mean 'what is filled in a lacquered box,' but rather 'what comes with two layers of eel, that is, the rice underneath, as well.'
また鰻重を「重箱に入れたもの」ではなく「飯の下にも鰻を敷いて重ねたもの」とする地域・店舗もある。