Nicene and Post-Nicene Fathers, Ser. II, Vol. XIV:
The Canons of the Synods of Sardica, Carthage, Constantinople, and Carthage Under St. Cyprian, Which Canons Were Received by the Council in Trullo and Ratified by II. Nice.: Canon CXXXIII

Canon CXXXIII.  (Greek cxxxiv.)

That a bishop should not rashly deprive anyone of communion.

As long as his own bishop will not communicate with one excommunicated, the other bishops should have no communion with that bishop, that the bishop may be more careful not to charge anyone with what he cannot prove by documentary evidence to others.

(Greek cxxxv.)

Bishop Aurelius said:  According to the statutes of this whole assembled council, and the opinion of my littleness, it seems good to make an end of all the matters of the whole of the before-manifested title, and let the ecclesiastical acts receive the discussion of the present day’s constitution.

p. 506 And what things have not yet been expressed (“treated of” in the Greek) we shall write on the next day through our brethren, Bishop Faustinus and the Presbyters Philip and Asellus to our venerable brother and fellow-bishop Boniface; and they gave their assent in writing.

Notes.

Ancient Epitome of Canon CXXXIII.

If a bishop deprives of communion an unconvicted man, he shall likewise be deprived of communion with his fellows.

Johnson.

Never was a more impartial law made, especially when all the legislators were bishops except two.  There were 217 bishops, and two priests, being legates from the bishop of Rome.

The Greeks make a canon of the ratifications, and reckon no more than 135.  Aurelius, Bishop of Carthage, subscribes first, and after him 217 bishops, then Asellus and Philippus, priests, legates of the church of Rome.  And it does not appear that any other priests were present in any of the councils, mentioned in the body of this code; but there is several times notice taken of the deacons who stood by.