Canon 10
About the impossibility of the fallen (those who have renounced) to be in the sacred rank.
If some of those who fell were promoted to the clergy, either through ignorance or with the knowledge of those who made them, this does not weaken the power of the church rule. When this becomes known, these are subject to eruption.
Greek original
Ὅσοι προεχειρίσθησαν τῶν παραπεπτωκότων, κατ᾿ ἄγνοιαν, ἢ καὶ προειδότων τῶν προχειρισαμένων, τοῦτο οὐ προκρίνει τῷ κανόνι τῷ ἐκκλησιαστικῷ· γνωσθέντες γάρ, καθαιροῦνται.
Parallel canons
Ап.62IВс.9Анкир.112Петра10Вас.73Григ.Нисск.2