Catechism of the Catholic Church §433 — excerpt
The name of the Saviour God was invoked only once in the year by the high priest in atonement for the sins of Israel, after he had sprinkled the mercy seat in the Holy of Holies with the sacrificial blood.
This translation is under copyright, so only the cited words are quoted here. Follow the link for the full text. Translation: English translation of the Catechism of the Catholic Church, 2nd ed. (Libreria Editrice Vaticana), as posted at vatican.va.