9 As to the faithful, We strenuously exhort them after Sacramental confessiondevoutly to partake of the Bread of Angels for the benefit of the souls inpurgatory. We grant by Our Apostolic authority a plenary indulgence to be gainedby such of the faithful, applicable to the dead, and the favour of a privilegedaltar to all those who, as has been said before, say Mass.
Source: Quod Anniversarius (Vatican.va)