In recent issues of AD2000, reference has been made to the continuing dissent from the Pope's ruling that the Church has no authority to confer priestly ordination on women. Despite the precise wording of Ordinatio Sacerdolatis, the dissenters claim that the Holy Father's ruling is a matter of discipline which is subject to future amendment.
On 25 October 1995, Cardinal Ratzinger issued a Responsum to Ordinatio Sacerdolatis which contained the following passage: "In response to this precise act of the Magisterium of the Roman Pontiff, explicitly addressed to the entire Catholic Church, all members of the faithful are required to give their assent to the teaching stated therein. To this end, the Congregation for the Doctrine of the Faith, with the approval of the Holy Father, has given an official reply on the nature of this assent; it is a matter of full definitive assent, that is to say, irrevocable, to a doctrine taught infallibly by the Church.
"In fact, as the reply explains, the definitive nature of this assent derives from the truth of the doctrine itself, since, founded on the written Word of God, and constantly held and applied in the Tradition of the Church, it has been set forth infallibly by the ordinary universal Magisterium (Lumen Gentium, 25). Thus, the reply specifies that this doctrine belongs to the deposit of the faith of the Church."
It seems obvious to me that papal approval of the responsum gives it the same credibility as if it were written by the Holy Father.