Index Librorum Prohibitorum
The Index Librorum Prohibitorum (English: Index of Forbidden Books) was a changing list of publications deemed heretical or contrary to morality by the Sacred Congregation of the Index (a former dicastery of the Roman Curia); Catholics were forbidden to print or read them, subject to the local bishop. Catholic states could enact laws to adapt or adopt the list and enforce it.
Source: Wikipedia — Index Librorum Prohibitorum (CC BY-SA 4.0)