Let’s wrap up the introduction to the DPPL, with a note that the local bishop is the key person, the go-between if you will, for Church teaching on liturgy and devotion, and knowing the pulse of local piety. It makes the best sense to do this, the bishop, along with pastoral leadership:
21. Manifestations of popular piety are subject to the jurisdiction of the local Ordinary. It is for him to regulate such manifestations, to encourage them as a means of assisting the faithful in living the Christian life, and to purify and evangelize them where necessary. He is also to ensure that they do not substitute for the Liturgy nor become part of the liturgical celebrations (Cf. Vicesimus Quintus Annus 18; Varietates Legitimae 45). The local ordinary also approves the prayers and formulae associated with acts of public piety and devotional practices (Cf. canon law 826.3). The dispositions given by a particular local Ordinary for the territory of his jurisdiction are for the particular Church entrusted to his pastoral care.
A concern about people promoting devotions, even the clergy within a diocese:
Hence, the faithful – both clerics and laity, either as groups or individuals, may not publically promote prayers, formulae or private initiatives without the permission of the ordinary.
This presumes that bishops possess the theological and pastoral competence to make decisions, and in many of not most places, bishops have the authority, certainly. But others have a better view of one or both.
In accordance with the Apostolic Constitution Pastor Bonus, n.70, it is the competence of the Congregation for Divine Worship and the Discipline of the Sacraments to assist the Bishops in matters relating to prayers and devotional practices of the Christian people, as well as to issue dispositions in those cases surpassing the bounds of a particular Church, and in imposing subsidiary provisions.
And as many of us church geeks know, Pastor Bonus is getting a serious revision.
The full document, the Directory on Popular Piety and the Liturgy, is online at the Vatican site.