Pope Francis has changed church regulations to explicitly allow women and girls to participate in the Easter Week foot-washing ritual.
His decree comes after the pontiff shocked many Catholics by performing the rite on women and Muslims just weeks after he was elected.
Proponents of women's ordination hailed Francis' decree, while traditionalist Catholics warned that it would weaken the church and lead to questions about the inviolability of the all-male priesthood.
Vatican rules for the Holy Thursday rite had long called for only men to participate. Popes past and many priests traditionally performed the ritual on 12 Catholic men, recalling Jesus' 12 apostles and further cementing the doctrine of an all-male priesthood.
Shortly after he was elected, Francis raised conservative eyebrows by performing the rite on men and women, Catholics as well as Muslims, at a 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 better 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." It specifies that the group can include "men and women, and ideally young and old, healthy and sick, clerical, consecrated and lay."
Priests must make sure that those participating are instructed beforehand as to the significance of the gesture, the decree said.
While the phrase "people of God" generally refers to baptised Christians, the decree also said that pastors should instruct "both the chosen faithful and others so that they may participate in the rite consciously actively and fruitfully." That could suggest that the rite could be open to non-Catholics as well.
In an accompanying letter, dated December 20, 2014 but released on Thursday, Francis wrote to the head of the liturgy office saying 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."
