Nicene and Post-Nicene Fathers, Ser. II, Vol. XIV:
The Third Ecumenical Council:  The Council of Ephesus.: Canon VI

Canon VI.

Likewise, if any should in any way attempt to set aside the orders in each case made by the holy Synod at Ephesus, the holy Synod decrees that, if they be bishops or clergymen, they shall absolutely forfeit their office; and, if laymen, that they shall be excommunicated.

Notes.

Ancient Epitome of Canon VI.

If any layman shall resist the Synod, let him be excommunicated.  But if it be a cleric let him be discharged.

How courageous the passing of this canon was can only be justly appreciated by those who are familiar with the weight of the imperial authority at that day in ecclesiastical matters and who will remember that at the very time this canon was passed it was extremely difficult to say whether the Emperor would support Cyril’s or John’s synod.

p. 231 Observation of the Roman Editors (Ed: 1608).

In the Vatican books and in some others only these six canons are found; but in certain texts there is added, under the name of Canon VII., the definition of the same holy Synod put forth after the Presbyter Charisius had stated his case, and for Canon VIII. another decree of the synod concerning the bishops of Cyprus.

Observation of Philip Labbe, S.J.P.

In the Collections of John Zonaras and of Theodore Balsamon, also in the “Code of the Universal Church” which has John Tilius, Bishop of St. Brieuc and Christopher Justellus for its editors, are found eight canons of the Ephesine council, to wit the six which are appended to the foregoing epistle and two others:  but it is altogether a subject of wonder that in the Codex of Canons, made for the Roman Church by Dionysius Exiguus, none of these canons are found at all.  I suppose that the reason of this is that the Latins saw that they were not decrees affecting the Universal Church, but that the Canons set forth by the Ephesine fathers dealt merely with the peculiar and private matters of Nestorius and of his followers.

The Decree of the same holy Synod, pronounced after hearing the Exposition [of the Faith] by the Three hundred and eighteen holy and blessed Fathers in the city of Nice, and the impious formula composed by Theodore of Mopsuestia, and given to the same holy Synod at Ephesus by the Presbyter Charisius, of Philadelphia: