The Canons of the Council in Trullo; Often Called The Quinisext Council 55Canon LV.

Since we understand that in the city of the Romans, in the holy fast of Lent they fast on the Saturdays, contrary to the ecclesiastical observance which is traditional, it seemed good to the holy synod that also in the Church of the Romans the canon shall immovably stands fast which says: "If any cleric shall be found to fast on a Sunday or Saturday (except on one occasion only) he is to be deposed; and if he is a layman he shall be cut off."