[RnMomof7]

V2 was an ecumenical council and as such is considered to be infallible ...

and like it or not it was infallible in the matters of faith and morals for Roman Catholics

[Wyrd bið ful aræd]

Only solemn definitions regarding faith and morals are infallible -- an ecumenical council is by no means infallible in and of itself, simply by merit of being an ecumenical council.