While "clerics and members of institutes of consecrated life are bound to observe their own rite faithfully", priests are occasionally given permission to celebrate the liturgy of a rite other than the priest's own rite, by what is known as a grant of "biritual faculties". The reason for this permission is usually the service of Catholics who have no priest of their own rite. Thus priests of the Syro-Malabar Church working as missionaries in areas of India in which there are no structures of their own Church, are authorized to use the Roman Rite in those areas, and Latin-Rite priests are, after due preparation, given permission to use an Eastern rite for the service of members of an Eastern Catholic Church living in a country in which there are no priests of their own particular Church. Popes are permitted to celebrate a Mass or Divine Liturgy of any rite in testament to the Catholic Church's universal nature. John Paul II celebrated the Divine Liturgy in Ukraine during his pontificate.