§1. A Catholic school is understood as one which a competent ecclesiastical authority or a public ecclesiastical juridic person directs or which ecclesiastical authority recognizes as such through a written document.
§2. The instruction and education in a Catholic school must be grounded in the principles of Catholic doctrine; teachers are to be outstanding in correct doctrine and integrity of life.
§3. Even if it is in fact Catholic, no school is to bear the name Catholic school without the consent of competent ecclesiastical authority.
Source: Code of Canon Law (Vatican.va)