The Greek-speaking Orthodox have collected canons and commentaries upon them in a work known as the Pēdálion (Greek: Πηδάλιον, "Rudder"), so named because it is meant to "steer" the Church. The Orthodox Christian tradition in general treats its canons more as guidelines than as laws, the bishops adjusting them to cultural and other local circumstances. Some Orthodox canon scholars point out that, had the Ecumenical Councils (which deliberated in Greek) meant for the canons to be used as laws, they would have called them nómoi/νόμοι (laws) rather than kanónes/κανόνες (rules), but almost all Orthodox conform to them. The dogmatic decisions of the Councils, though, are to be obeyed rather than to be treated as guidelines, since they are essential for the Church's unity.
What decisions of the councils are to be treated as guidelines?