“Despite the fact that the indelible mark theory acquired dogmatic formulation in the Council of Trent,18 in most circles of the Roman Catholic Church, after the Second Vatican Council, the foundational framework of effecient causality and ex opere operato, which gave rise to such an understanding of priesthood, is reckoned as belonging to a bygone age and abandoned for a more dynamic and ecclesiological approach of sacrament.19
It should be mentioned in this connection that as far as we know, no evidence concerning the indelible mark theory can be found in Patristic teaching. On the contrary, the canonical data leave no doubt that a defrocked priest or bishop, after the decision of the Church to take back his priesthood, returns to the rank of the laity. The anathematized or the defrocked are in no way considered to maintain their priesthood.”
The site no doubt takes a stance in contradiction to Catholic declarations made at Trent.
“CANON IV.–If any one saith, that, by sacred ordination, the Holy Ghost is not given; and that vainly therefore do the bishops say, Receive ye the Holy Ghost; or, that a character is not imprinted by that ordination; or, that he who has once been a priest, can again become a layman; let him be anathema.”