Canon 8
If an excommunicated presbyter dares to celebrate, he should be anathematised.
Felix, bishop of Selemsela, said: We should not allow, if a presbyter censured [or excommunicated] by his bishop, inflated by his pride, thought that he could offer God's sacrifice separately or erect another altar, believing that he could act against the ecclesiastic faith and discipline, that he should go unpunished.
Bishop Geneclius said: What our brother Felix said is necessary for the ecclesiastical discipline, and consonant with the faith; therefore, please declare what you think about it.
All the bishops said: if a presbyter was [excommunicated or] censured by his superior, he should refer to neighbouring bishops so that his cause may be heard by them and he can be reconciled with his bishop through them.
But if he did not do it, and, God forbid!, inflated by pride, he separated himself from the bishop of his communion and separately, with others, offered to God sacrifice, creating a schism, [dismissed from that place] he will be anathematised. He should also be removed far from the city in which he lived, so that the ignorant and the simple were not deceived by the devilish fraud.
As the Apostle said: there is one church, one faith, one baptism.
And if he has genuine grievances against his bishop, there should be an inquiry into it.
(trans. S. Adamiak)