Pope Francis has changed church regulations to correspond to his rule-breaking celebration of the Easter Week ritual of washing the feet of men and women, Christians and not, in a sign of universal service.

Vatican rules for the Holy Thursday rite had long called for only men to participate, and popes past and many priests traditionally performed the ritual on 12 Catholic men, recalling Jesus' 12 apostles.

Shortly after he was elected, Francis raised conservative eyebrows by performing the rite on men and women, Christians as well as Muslims, at a Roman juvenile detention facility in Rome.

He has continued to include men and women, young and old, sick and healthy and people of different faiths, travelling each year to encounter them to show his willingness to serve. It was a tradition he began as archbishop in Buenos Aires.

On Thursday, the Vatican published a decree from the Vatican's liturgy office introducing an "innovation" to the church's rules that corresponds to Francis' way of doing things.

The decree said the rite can now be performed on anyone "chosen from among the people of God," Catholic or not. Priests must only make sure that those participating are instructed beforehand as to the significance of the gesture.

It specifies that the group can include "men and women, and hopefully young and old, healthy and sick, clerical, consecrated and lay."

In an accompanying letter, dated Dec. 20 but released Thursday, Francis wrote that he wanted to change the current rules "to fully express the significance of Jesus' gesture, his giving of himself to the end for the salvation of the world and his unending charity."