[Canticle_of_Deborah]

That's funny because a commission of nine cardinals created by Pope John Paul II in the 90s studied the issue and found the Tridentine Mass had never been abrogated. I believe Benedict/Ratzinger was on the commission.

You must know something they don't.

[ninenot]

Both you and gbc are correct.

"Derogation" is not the same as "abrogation," and that's not a smartass observation, despite my inclinations...

The Old Rite was 'derogated,' but NEVER 'abrogated.' IOW, the NO replaced it, without a formal declaration that the Old Rite could NOT be used.

Homely analogy--you buy a second car and decide to use IT in preference to your first one. The first car was 'derogated.' Nothing wrong with it, you didn't sell or get rid of it--you just don't USE it.

[gbcdoj]

Here is the reference to the SCDW's letter, pp. 103-5 of The Problem of the Liturgical Reform. I have excised the SSPX arguments opposing it, which one can read in the book if he so wishes. My apologies for misremembering their conclusion and thus mixing up the terms.

When the matter is discussed, several documents in addition to the Missale Romanum are invariably cited ... lastly, a letter emanating from the Sacred Congregation of Divine Worship addressed to the Bishop of Siena in 1999. ... the letter of the Sacred Congregation for the Divine Worship to the Bishop of Siena in 1999 acknowledges that “in the apostolic constitution Missale Romanum, no explicit formula of abrogation of the Roman missal so-called of St. Pius V occurs.” ... According to Canon 20 of the Code of Canon Law, a later law supersedes or, to use the technical word, “obrogates” an earlier law if it integrally reorders the whole subject matter of the earlier law, and supplants it. The letter of the Sacred Congregation for Divine Worship to the Bishop of Siena in 1999 seems to maintain that the Tridentine missal would have been suppressed by a form of obrogation. ... This letter asserts in the first place that “if the will of the Pontiff had been to leave in force the preceding liturgical forms as an alternative that could be freely chosen, he should have said so explicitly.” ... This letter asserts that documents subsequent to the constitution Missale Romanum confirm the obligatory character of Paul VI’s missal. ... This letter asserts that “usage” manifests the obligatory character of Paul VI’s missal. ... This letter asserts that the obligatory character of Paul VI’s missal can be seen by comparing it to the situation described in Canon 6, §1, No. 4 taken together with Canon 19 [I think this was probably 20?].

Hopefully B16 can conclude a universal indult if negotiations with the SSPX get going again, but the SCDW's arguments have convinced me that the "immemorial custom"/"Quo Primum never suppressed" arguments are bunk. Here are the referenced canons:

Can. 6 §1 When this Code comes into force, the following are abrogated: ... 4° any other universal disciplinary laws concerning matters which are integrally reordered by this Code.

Can. 19 If on a particular matter there is not an express provision of either universal or particular law, nor a custom, then, provided it is not a penal matter, the question is to be decided by taking into account laws enacted in similar matters, the general principles of law observed with canonical equity, the jurisprudence and practice of the Roman Curia, and the common and constant opinion of learned authors.

Can. 20 A later law abrogates or derogates from an earlier law, if it expressly so states, or if it is directly contrary to that law, or if it integrally reorders the whole subject matter of the earlier law. A universal law, however, does not derogate from a particular or from a special law, unless the law expressly provides otherwise.