In the first Christian centuries, the church was a Bishop's church in the Diocese of Trent. The Bishop of Trent was from 10-27-1803 also a Prince of the Holy Roman Empire (The German Nation) and Ecclesial Principality. Since the 20th century of the previous century, the Diocese was raised to an Archdiocese. In Saint Maria Maggiore the Council took place in its third period from 1582-1563. In this church there were various conclusions made, which after the Protestant Revolt and schism led to a phase of renewal and a new blooming.
"The excuse, to remove the kneelers and communion rail is doubly astonishing, since this after all happens to be a church, in which the Council met, which strengthened the pious knee in the Holy Liturgy and opposed the human conception of the Reformation [Protestant Revolt]," says Libertá e Pensiero..
It reads in the General Instruction to the Missale Romanum of 1975:
Movements And Postures
20. The uniformity in standing, kneeling, or sitting to be observed by all taking part is a sign of the community and the unity of the assembly; it both expresses and fosters the spiritual attitude of those taking part.
21. For the sake of uniformity in movement and posture, the people should follow the directions given during the celebration by the deacon, the priest, or another minister. Unless other provision is made, at every Mass the people should stand from the beginning of the entrance song or when the priest enters until the end of the opening prayer or collect; for the singing of the Alleluia before the gospel; while the gospel is proclaimed; during the profession of faith and the general intercessions; from the prayer over the gifts to the end of the Mass, except at the places indicated later in this paragraph. They should sit during the readings before the gospel and during the responsorial psalm, for the homily and the presentation of the gifts, and, if this seems helpful, during the period of silence after communion. They should kneel at the consecration unless prevented by the lack of space, the number of people present, or some other good reason.
But it is up to the conference of bishops to adapt the actions and postures described in the Order of the Roman Mass to the customs of the people. But the conference must make sure that such adaptations correspond to the meaning and character of each part of the celebration.
Edit: It's not like anyone reads the rules, though.
Translated from, katholisches, which got the story from an Italian site...