I've had a brilliant idea - yet another one - about the Holy Father's brilliant decision to rename the Extraordinary Form the Vetus Ordo.
Could we take the formula Vetus Ordo to refer to any Mass of the Latin Rite celebrated according to the rubrics that existed at any time before the publication of the Novus Ordo? This would include several sub-varieties; one could multiply them endlessly, but practically speaking, these ...
(a) ("1965") the Mass celebrated by those who follow the use of 1965 (I believe there are communities which celebrate this by indult), according to the Ordo Missae which was promulgated that year (and ordered to be printed in future printings of the Missale Romanum: ...et in novis Missalis romani editionibus assumeretur ...). If Summorum Pontificum had not specifically mentioned 1962, this rite of 1965 would have been naturally, and logically, assumed to be the final form of the Old Mass before the introduction of the Novus Ordo*. It is the form used by Archbishop Lefebvre before he subsequently decided to revert to 1962. It omits the psalm Iudica me and the Last Gospel; simplifies the gestures at the Doxology of the Canon; introduces the Forma Ambrosiana ("Corpus Christi R Amen") at Communion. Then there is
(b) ("the Extraordinary Form") the rite of 1962. There are two forms of this. (bi) The form authorised as the Editio typica was authorised and published before the Council. It lacks S Joseph in the Communicantes. But (bii) dates from December, after the start of the Council, when B John XXIII added S Joseph to the Canon. Logically, (bi) fits the prescriptions of Summorum pontificum. But (bii) is, I think, most commonly although illegally used by those celebrating "1962". As for
(c), I must be discreet here. This is for your eyes only. Not to be mentioned outside these four walls. There are those, dangerous men, who use the rite as it was before Pius XII and his ally Bugnini got to work on it. (I shall not enable comments which disclose group or individual identities.)
"Vetus Ordo" suits as an umbrella to refer to all of these. And version (c) we could call ... what? Usus authenticior?
*I presume Pope Benedict XVI picked upon "1962" rather than 1965 in his motu proprio quite simply because His Excellency Archbishop Marcel Lefebvre had previously done so; an example of his gentle and ecumenical courtesy; his desire to make things as easy as he possibly could for the SSPX.
The alterations mandated in 1967 do not, in my fallible view, constitute another variety of the Vetus Ordo because they were never printed in the form of an Ordo Missae and were not ordered to be incorporated into editions of the Missale Romanum (indeed, the accompanying Instructio includes the words firmis manentibus actualibus liturgicis libris).