OK, two points here. 

1) Trent says that the one who's accursed is the one who says that the rites can be changed, not the one who changes them.

2) Trent says they can't be changed by the "ministers" (aka those performing the Rites), not necessarily the popes.

As for Montini being cursed, the Church always presumes what is known in the public forum and does not delve into "possible hypothetical deathbed conversions".

Dear Ladislaus,
English translations are deceiving!  In the original Latin, "quiscuмque" means "whosoever"; not "every or any" pastor of the churches. (Canon XIII, Seventh Session).  As Dom Hesse said, "That means you, too, Pope!"

 Additionally, the Creed of the Council of Trent states that:  "I also receive and admit the accepted and approved rites of the Catholic Church in the solemn administration of all the aforesaid sacraments."  Denzinger 996 (1957 ed.) All popes are bound by the Profession of Faith (Credo).

CANON XIII.-If any one saith, that the received and approved rites of the Catholic Church, wont to be used in the solemn administration of the sacraments, may be contemned, or without sin be omitted at pleasure by the ministers, or be changed, by every pastor of the churches, into other new ones; let him be anathema.

There are two parts to it ... whoever says and whichever minister/pastor changes.  Could you post the Latin?

That quoted phrase means that IF a Catholic stated something substantially the same as the anathematized statement and refused to listen to two warnings by a competent authority, then the competent authority could anathematize that Catholic using the ceremony in the Roman Pontifical. Anathematization of a Catholic does not happen automatically.

Here is the quote from the Catholic Encyclopedia page on anathema explaining that:

The book to read on the topic is the 1917 Code of Canon Law. The same 3 levels of excommunication are outlined in Canon 2314. And some of the details about the consequences of each level can be found in Canons 2257-2267 (and other places in the Code).

Here is an online version of the 1917 Code of Canon Law (English):

https://cdn.restorethe54.com/media/pdf/1917-code-of-canon-law-english.pdf

Dear Angelus,
Thank you for your valuable directions. 1917 Canon Law compiled and explained by Ellis and Bouscaren states: "Excommunication. (...) It is also called anathema, especially if it is inflicted with the solemnities described in the Roman Pontifical." (c.2257, p2) page.876

  This statement presupposes a possibility that someone can incur an anathema without official proclamation. It is in agreement with the colloquial understanding of the passage from the Holy Scriptures that Viva Cristo Rey kindly posted on the thread Anathema!: "But though we, or an angel from heaven, preach a gospel to you besides that which we have preached to you, let him be anathema." Galatians 1;8
Does Bishop Paul suggest that Galatians go to Peter to proclaim an official judgement? What if "Peter" himself, by changing all the rites of sacraments, incurs the anathema of the Council of Trent? To whom are the faithful to turn to if, not only Peter, but also his successors, being infiltrators and enemies of the Church, continue in the error "Peter" introduced?

  There has to be another source of information on anathema and its practical application. The encyclopaedical knowledge had to come from somewhere.

  We agreed that the new rites of sacraments are illegitimate. The Church has never used an illegitimate Pontifical to convey a sacrament of Order. Dom Hesse was of the opinion that so-called Conciliar Church was a schismatic sect with new rites of sacraments and new magisterium. What he failed to notice is that the Church has never used schismatic books to administer the sacrament of Order. Baptism is a problematic example, because its administration in an emergency does not require use of the Rituale. Also, the heretics and schismatics observing the custom of connecting water with the essential form, are doing what the Church does. Try to ordain a priest or consecrate a bishop without the Pontificale, especially after Pope Pius XII in Sacramentum Ordinis insists that the whole rite be used and nothing omitted.

By using the illicit (schismatic) Pontifical, whatever adjective we use to indicate any difference from the one codified by Trent, a bishop will manifest his intention. It does not matter that he is ignorant, thinks differently, or simply wants to ordain a priest to the order of Melchizedek. The Church will not judge his internal condition. The fact is that he uses the book that he was not supposed to use. He is obligated to know the Creed of the Council of Trent and apply Canon XIII of the Seventh Session.

 Archbishop Lefebvre is a good example. He could have continued to use Novus Ordo books. The example of Bp. Antonio de Castro Mayer not ever compromising is a great witness that the Apostolic Succession could be continued without a break. Archbishop Thuc, though faltering in his resolve from time to time, has provided a line of valid bishops.

Yes, if we apply the 1917 Canon Law to the sect of the "permanent deacons", "priests", and "bishops" of the New Order, Pope Paul VI and his successors are tolerandi until they become vitandi. However we slice it, they are under the anathema of Trent. In the past the faithful would know the Creed and apply it in life. As long as most of those who want to be Catholic are ignorant, the chastisement will continue. I am continually learning and I appreciate your help and Matthew's forum. God Bless!

Dear Angelus,
Some excommunicated persons are vitandi; some excommunicated persons are tolerati (canon 2258.p1). page 876.
The excommunication concerns those who committed the crime, but are not yet judged = tolerati; and those judged = vitandi. Both are excommunicated. A person may incur excommunication ipso facto and canon 2258 takes that into account.

If a heretic bishop who has the indelible mark takes the Roman Pontifical and fulfills all the requirements, he will convey the order validly. When the same bishop, instead of using the Roman Pontifical codified by Trent, takes in his hands the Novus Ordo Pontifical and proceeds to ordain or consecrate, he will not validly ordain or consecrate because of manifest invalid intention. By the act of using the illicit book, he shows his intention.

 We agreed that the rites of the sacraments introduced by Pope Paul VI are illicit. Those rites are contained in the Novus Ordo Pontifical, making it illicit.  It is the use of the books that shows the intention. The Church never used an illicit book to administer any Sacrament. It is an invalidating intention, because the minimum required by the Church is "to do what the Church does". Notice that your example involves a heretic, and we know from the encyclical, "Mystici Corporis" of Pope Pius XII, that heretics, schismatics, and apostates are outside the Church. That bishop could also be toleratus if his heresy is in fact, but not judged; or vitandus if the Church already pronounced the verdict.

Thank you so much for this discussion!  We really appreciate your help.

Anathema remains a major excommunication which is to be promulgated with great solemnity. A formula for this ceremony was drawn up by Pope Zachary (741-52) in the chapter Debent duodecim sacerdotes, Cause xi, quest. iii. The Roman Pontifical reproduces it in the chapter Ordo excommunicandi et absolvendi, distinguishing three sorts of excommunication: minor excommunication, formerly incurred by a person holding communication with anyone under the ban of excommunication; major excommunication, pronounced by the Pope in reading a sentence; and anathema, or the penalty incurred by crimes of the gravest order, and solemnly promulgated by the Pope. In passing this sentence, the pontiff is vested in amice, stole, and a violet cope, wearing his mitre, and assisted by twelve priests clad in their surplices and holding lighted candles. He takes his seat in front of the altar or in some other suitable place, amid pronounces the formula of anathema which ends with these words: "Wherefore in the name of God the All-powerful, Father, Son, and Holy Ghost, of the Blessed Peter, Prince of the Apostles, and of all the saints, in virtue of the power which has been given us of binding and loosing in Heaven and on earth, we deprive N-- himself and all his accomplices and all his abettors of the Communion of the Body and Blood of Our Lord, we separate him from the society of all Christians, we exclude him from the bosom of our Holy Mother the Church in Heaven and on earth, we declare him excommunicated and anathematized and we judge him condemned to eternal fire with Satan and his angels and all the reprobate, so long as he will not burst the fetters of the demon, do penance and satisfy the Church; we deliver him to Satan to mortify his body, that his soul may be saved on the day of judgment." Whereupon all the assistants respond: "Fiat, fiat, fiat." The pontiff and the twelve priests then cast to the ground the lighted candles they have been carrying, and notice is sent in writing to the priests and neighbouring bishops of the name of the one who has been excommunicated and the cause of his excommunication, in order that they may have no communication with him. Although he is delivered to Satan and his angels, he can still, and is even bound to repent. The Pontifical gives the form for absolving him and reconciling him with the Church. The promulgation of the anathema with such solemnity is well calculated to strike terror to the criminal and bring him to a state of repentance, especially if the Church adds to it the ceremony of the Maranatha.

Dear Angelus,
The word "especially" does not mean "only" or "solely", in fact it indicates that there can be other occasions when anathema could be proclaimed. The text says: "... It is also called anathema, especially if it is inflicted with the solemnities described in the Roman Pontifical" (c.2257, p2). There could be a simple proclamation from the Pope without engaging the Ritual. There could be a verdict from the tribunal of the Inquisition. There could be a judgement of a bishop of a diocese. Yes, none of these examples could make the offender vitandus, but they certainly would make him ferre sententiae (adjuticated) toleratus.
I do not have the Latin text of the canon. If the Latin text states that: It is called anathema, only if it is inflicted with solemnities described in the Roman Pontifical, I stand corrected. As it is, the English text does not state that.

Pope Leo XIII could not use the argument of invalid intention for the simple reason that before the Council of Trent, there was not an explicit law forbidding an introduction of a new rite of a sacrament. Bishop Cranmer sneaked his Godly Order before anathema could stop it. Canon XIII of the Seventh Session was introduced precisely to remedy such abuses. Pope Saint Pius V made sure that all of the rites of the sacrament of the Eucharist that were not older than 200 years would be removed. Thus, all the novelties and new Masses were gone. From then on, both in the East and the West, no new rites of sacraments were to be introduced. Whosoever would even say that the new ones be introduced would be anathema. Such a person, even a pope, would become: toleratus (non judged or adjudicated) or vitandus if the Pope used the rite from the Roman Ritual.

I cannot think at present of any other illicit book besides the Novus Ordo Pontifical that a Catholic Bishop could use to ordain or consecrate. Who else introduced a liturgical compilation of all the rites of sacraments after the Council of Trent?

Canon 2257 is saying that an "anathema" can be announced in at least two ways:

1. "with the solemnities described in the Roman Pontifical."
2. using some other process consistent with Canon 2258.

Here is what Canon 2258 says:

§ 1. Some excommunicates are banned [vitandi], others tolerated.

§ 2. No one is banned [vitandus] unless so named as an excommunicate by the Apostolic See, the
excommunication is publicly announced, and it is expressly stated in the decree or sentence that
he must be avoided with due regard for the prescription of Canon 2343, § 1, n. 1.

Since an "anathema" is a form of condemnation reserved for vitandi, and since a vitandi must be "named as an excommunicate by the Apostolic See," your theory about "an anathema without official proclamation" contradicts Canon Law. The Church has spoken.

It was this venerable ordination rite, as preserved in the English varieties of the Roman Pontifical, which was in use in the country when Henry VIII began his assaults on the ancient religion. He did not himself venture to touch it, but in the next reign it was set aside by Cranmer and his associates who, under the rule of Somerset and Northumberland, were engaged in remodelling the whole fabric of the Church of England to suit their extreme Protestant conceptions. These men pronounced the ancient forms to be utterly superstitious and requiring to be replaced by others more in conformity with the simplicity of the Gospel. Hence the origin of the Edwardine Ordinal, which, under the sanction of the Act of 1550, was drawn up by "six prelates and six other men of the realm learned in God's law, by the King's Majesty to be appointed and assigned".

This new rite underwent some further changes two years later, and was thus brought into the form in which it remained till the year 1662, when it was somewhat improved by the addition of clauses defining the nature of the orders imparted. As the Ordinal of 1550 had no lasting influence on the country, we may disregard it here, as we may also disregard, as of less consequence, the rite for the ordination of deacons.

In the Ordinal of 1552 the "essential form", that is, the form adjoined to the imposition of hands, was, in the case of the priesthood, merely this: "Receive the Holy Ghost.