Catholic Encyclopedia (1913)/Apostolic Letters
(Litterae apostolicae).
1. The letters of the Apostles to Christian communities or those in authority, i.e. the Pauline Epistles, including the Epistle to the Hebrews, together with the seven Catholic epistles of the other Apostles.
2. Documents issued by the Pope or in his name, e.g. bulls and briefs.
F.M. RUDGE