§1. It is for the competent ecclesiastical authority alone to erect associations of the Christian faithful which propose to hand on Christian doctrine in the name of the Church or to promote public worship, or which intend other purposes whose pursuit is of its nature reserved to the same ecclesiastical authority.
§2. Competent ecclesiastical authority, if it has judged it expedient, can also erect associations of the Christian faithful to pursue directly or indirectly other spiritual purposes whose accomplishment has not been sufficiently provided for through the initiatives of private persons.
§3. Associations of the Christian faithful which are erected by competent ecclesiastical authority are called public associations.
Source: Code of Canon Law (Vatican.va)