(Numbers are paragraph numbers in the Enchiridion Symbolorum, The Sources
of Catholic Dogma, 30th edition, unless otherwise indicated).

From the Errors of the Synod of Pistoia, condemned in the Constitution
"Auctorem fidei", Aug. 28, 1794 by Pope Pius VI.

1533 The proposition of the Synod by which it shows itself eager to
remove the cause through which in part, there has been induced a for-
getfulness of the principles relating to the order of the liturgy, "by
recalling it (the liturgy) to a greater simplicity of rites, by express-
ing it in the vernacular language, by uttering it in a loud voice"; as 
if the present order of liturgy, received and approved by the Church, 
had emanated in some part from the forgetfulness of the principles by 
which it should be regulated, -- rash, offensive to pious ears, insult-
ing to the Church, favorable to the chargers of heretics against it.

1566 The proposition asserting that "it would be against apostolic prac-
tice and the plans of God, unless easier ways were prepared for the peo-
ple to unite their voice with that of the whole Church"; if understood to
signify introducing the use of popular language into the liturgical pray-
ers, --false, rash, disturbing the order prescribed for the celebration 
of the mysteries, easily productive of many evils.

From the Council of Trent:

The Doctrine of the Most Holy Sacrifice of the Mass - Chapter 4 [The 
 Canon of the Mass]

942 And since it is fitting that holy things be administered in a holy 
manner, and this sacrifice is of all things the most holy, the Catholic
Church, that it might be worthily and reverently offered and received, 
instituted the sacred canon many centuries ago, so free from all error
[Can. 6], that it contains nothing in it which does not especially 
diffuse a certain sanctity and piety and raise up to God the minds of
those who offer it. For this consists both of the words of God, and of
the traditions of the apostles, and also of pious instructions of the  
holy Pontiffs.

953 Can. 6. If anyone says that the canon of the Mass contains errors, 
and should therefore be abrogated: let him be anathema.

956 Can. 9. If anyone says that the rite of the Roman Church, according
to which a part of the canon and the consecration are pronounced in a 
low tone, is to be condemned, or that the Mass ought to be celebrated 
in the vernacular only, or that water should not be mixed with the wine
that is to be offered in the chalice because it is contrary to the ins-
titution of Christ: let him be anathema.