Private revelation is revelation given by God to an individual person. Apparitions of Our Lady are considered private revelations. However, there is another type in which it is given to an individual mystic like Anne Catherine Emmerich or Mary of Agreda. The Church does not normally declare these private revelations given to individual mystics to be of supernatural origin, unlike Marian Apparitions which the Church does declare of supernatural origin (if the apparition is determined to be supernatural). However, Nihil Obstats are given to books that contain these revelations if they have no doctrinal or moral errors and are not contrary to the Church's teaching, allowing Catholics to read these books and learn from them. The following books, from private mystics, have a Nihil Obstat