Nicene and Post-Nicene Fathers, Ser. II, Vol. XIV:
The Canons of the Council in Trullo; Often Called The Quinisext Council.: Canon VI

Canon VI.

Since it is declared in the apostolic canons that of those who are advanced to the clergy unmarried, only lectors and cantors are able to marry; we also, maintaining this, determine that henceforth it is in nowise lawful for any subdeacon, deacon or presbyter after his ordination to contract matrimony but if he shall have dared to do so, let him be deposed.  And if any of those who enter the clergy, wishes to be joined to a wife in lawful marriage before he is ordained subdeacon, deacon, or presbyter, let it be done.

Notes.

Ancient Epitome of Canon VI.

If any ordained person contracts matrimony, let him be deposed.  If he wishes to be married he should become so before his ordination.

Aristenus points out how this canon annuls the tenth canon of Ancyra, which allows a deacon and even a presbyter to marry after ordination and continue in his ministry, provided at the time of his ordination he had in the presence of witnesses declared his inability to remain chaste or his desire to marry.  This present canon follows the XXVIth of the Apostolic canons.

The last clause of this canon, limited in its application to subdeacons, is found in the Corpus Juris Canonici, Gratian’s Decretum, Pars I., Dist. XXXII., c. vi.