by Pope John Paul II
Hail, all you faithful souls whose bodies rest here and elsewhere in dust; may Our Lord Jesus Christ, who redeemed you and us with His most precious Blood, vouchsafe to release you from your pains to unite you to the hosts of the angels; and there do you be mindful of us and suppliantly pray for us that we may join your company and be crowned along with you in heaven. Amen.
From: Prayers, Promises, and Devotions for the Holy Souls in Purgatory by Susan Tassone, p. 71
Note that a partial indulgence (applied exclusively to the holy souls) may be granted for visiting a cemetery and praying for the dead. From November 1 to 8 each year, a plenary indulgence may gained if all other usual conditions are met (i.e. sacramental confession, Eucharistic Communion and prayers for the pope within 20 days). A plenary indulgence removes all temporal punishment for sins which have been forgiven, while a partial indulgence remits only part of the temporal punishment. (Pieta Prayer Book, p.22)