The first of the Constitution’s “general norms” declares on whose authority modification of the Liturgy may be done. This may be a good point to review the categories contra legem, pro lege, and praeter legem in reference to liturgical practices and discuss the development of liturgical customs as we have witnessed them over the last fifty years.

Vatican website translation:

A) General norms
22. 1. Regulation of the sacred liturgy depends solely on the authority of the Church, that is, on the Apostolic See and, as laws may determine, on the bishop.
2. In virtue of power conceded by the law, the regulation of the liturgy within certain defined limits belongs also to various kinds of competent territorial bodies of bishops legitimately established.
3. Therefore no other person, even if he be a priest, may add, remove, or change anything in the liturgy on his own authority.

Latin text:

A) Normae generales
22. § 1. Sacrae Liturgiae moderatio ab Ecclesiae auctoritate unice pendet: quae quidem est apud Apostolicam Sedem et, ad normam iuris, apud Episcopum.
§ 2. Ex potestate a iure concessa, rei liturgicae moderatio inter limites statutos pertinet quoque ad competentes varii generis territoriales Episcoporum coetus legitime constitutos.
§ 3. Quapropter nemo omnino alius, etiamsi sit sacerdos, quidquam proprio marte in Liturgia addat, demat, aut mutet.

Slavishly literal translation:

A) General norms

22. 1. Oversight of the Sacred Liturgy depends upon the authority of the Church alone: indeed that is upon the Apostolic See and, according to the norm of law, upon the Bishop.

2. From the power granted by law, oversight of liturgical reality within established limits pertains also to lawfully constituted competent territorial groups of Bishops of varied types.

3. Therefore no other person, even if he should be a priest, may add, delete, or change anything in the Liturgy on his own authority.

The first set of general norms clarifies the levels of authority by which changes in the form of celebration of the Liturgy may be made. Since the Liturgy is the patrimony of the universal Church, any changes in its form of celebration concern the universal Church. Overseeing the celebration of the Liturgy is first entrusted to the Apostolic See (and we can trace how in the weeks and years following the promulgation of SC the pope entrusted the revision of the liturgical books of the Roman Rite to the Sacred Congregation for Rites/Congregation for Divine Worship [and the Discipline of the Sacraments] and to the Consilium for Implementing the Constitution on the Liturgy). Interestingly, Bishops (presumably Ordinaries) are also given authority to oversee the liturgy in their own diocese (thus being able, e.g., to establish particular days of prayer or penitence for their local Church). The third entity given responsibility for oversight of the liturgy is the territorial bishops’ conference; some of the competencies of these conferences will be noted later in SC.

I would ask help from the readers of Pray Tell in the interpretation of 22.3. First of all, “sacerdos” frequently refers to both bishops (episcopi) and priests (prebyteri). Do these prescriptions bind not only priests (and a fortiori deacons and the laity), but also bishops who are not Ordinaries from changing the celebratory form of the Liturgy? I have not been able to find the root word for “marte” in the expression “proprio marte.” The Vatican website translation offers “on his own authority” and I have no reason to doubt that translation, but I would like to know what word the Council Fathers used and what its range of meaning might be.