Nicæa I: canon VIII

Concerning those who have given themselves the name of Cathars, and who from time to time come over publicly to the catholic and apostolic church, this holy and great synod decrees that they may remain among the clergy after receiving an imposition of hands. But before all this it is fitting that they give a written undertaking that they will accept and follow the decrees of the catholic church, namely that they will be in communion with those who have entered into a second marriage and with those who have lapsed in time of persecution and for whom a period [of penance] has been fixed and an occasion [for reconciliation] allotted, so as in all things to follow the decrees of the catholic and apostolic church. Accordingly, where all the ordained in villages or cities have been found to be men of this kind alone, those who are so found will remain in the clergy in the same rank; but when some come over in places where there is a bishop or presbyter belonging to the catholic church, it is evident that the bishop of the church will hold the bishop's dignity, and that the one given the title and name of bishop among the so-called Cathars will have the rank of presbyter, unless the bishop thinks fit to let him share in the honour of the title. But if this does not meet with his approval, the bishop will provide for him a place as chorepiscopus or presbyter, so as to make his ordinary clerical status evident and so prevent there being two bishops in the city.