"Summorum Pontificum" is the title of the Papal, what was it, moto proprio from Benedict XVI
which stirred up so much commotion amongst
all the Catholics alienated by the Second Vatican Council.
A letter to the bishops accompanied this document -- 2007? --
about implementing the Pope's suggestions.

Within the religious orders with foundations which
found themselves on the margins, or beyond the pale,
with the disappearance of the traditional Latin Mass,
it was oddly enough two groups of Redemptorist[ine] religious
who considered that Benedict XVI was coming halfway to meet them,
and made what efforts they could to return the favor.
This was in direct response to "Summorum Pontificum."

What such monks/brothers and nuns understood from the document,
was that the traditional Latin Mass had in fact
never been done away with at the level at the Vatican,
and that anyone who told them the traditional Latin Mass was outlawed
had told them a falsehood.

Papa Stronsay, off of Scotland, has been mentioned in the previous post.
The Redemptorist monks and brothers there now observe the Latin Rite
and they do so in full communion with Rome,
thanks to Benedict XVI and his moto proprio.

Then there are the Redemptoristine cloistered nuns in Brazil:
however, that story, although it has a very happy ending,
is rather more tortured and complicated,
and deserves a separate posting.