Benedictio Dei omnipotentis, + Patris et Filii et Spiritus Sancti descendat super vos et maneat semper. Amen.
(May the Blessing of almighty God, Father, Son and Holy Ghost, come down over you and remain always. Amen.)
From what I remember from an old manual, there is a partial indulgence for those who devoutly kiss the hands of a newly ordained priest and receive his first blessing. For relatives to the second or third degree the indulgence is plenary under the usual conditions.
For a long time the SSPX has often said that the indulgence was plenary for everyone. The older manual contradicted this, but it is possible that the indulgence was made plenary for all at some point.