Correct!
Nevertheless, it is also true that the liturgical norms do allow some flexibility. With reference to the central and most important liturgical action, the Mass, for example, we can speak of three levels of flexibility. First, there are in the Missal and the Lectionary some alternative texts, rites, chants, readings and blessings from which the priest celebrant can choose. (cf GIRM 24, RS 39) Then there are choices left at the competence of the diocesan bishop or the Conference of Bishops. Examples are regulation of concelebration, norms regarding the distribution of Communion under both kinds, the construction and ordering of churches, translations and some gestures. (cf SC 38, 40; GIRM 387, 390) Some such alternatives require
recognitio from the Holy See. The most demanding level of variability concerns inculturation in the strictest sense. It involves action by the Conference of Bishops, after the conducting of deep interdisciplinary studies and
recognitio from the Holy See.
From here…
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