The Penitential Act at the beginning of the Mass is a liturgical rudiment of this previously sacramental confession. This private confession became the normal way in which this sacrament was and is practiced, with a strict seal of secrecy on the part of the priest. Sometimes the practice of the sacrament emphasized doing acts of penance, sometimes it emphasized making one's sorrow or contrition authentic, sometimes it emphasized confessing all one's serious (mortal) sins, sometimes it emphasized the power of the priest, In Persona Christi, to absolve the penitent of sin, and currently there are forms that include simply one-on-one confession to a priest or communal preparation and then one-on-one confession to a priest.