It is said that they have very strict rules such as a distinction between 'tsugi' (uncleanness) and 'kiyo' (cleanness) because this place is respected as a sanctuary which should avoid any impurity.
神聖な場所とされるが故に、たいへん穢れを嫌い、例えば「次清」の別などの厳格な規律が存在するとされる。