During the year of novitiate the novices are under the direct rule of the mistress of novices, whose authority over them is paramount, though she herself is of course under a vow of obedience to the superior. When a novice receives a visit from one in the world she is accompanied by the "mistress," and if the visitor be a near relation and a woman the curtain behind the grating is withdrawn; if only a friend, the visitor does not even see the nun, as the thick curtain is drawn, and the only communication possible is by speech. It is generally possible, on any necessity arising, to obtain a special permission to break through the rule of enclosure: this is done by applying to the superior-general of the order, or in Rome to the Holy Father, whose authority naturally supersedes all others. Sometimes the power to dispense lies with the local superior, but it is a prerogative seldom used, and wisely so. In every order the internal government of each house is of an elective form, but when once chosen the superiors exercise absolute authority. The community meets every three years (in some orders every year) and chooses by vote a superioress, an assistant superioress and a mistress of novices. Only the professed nuns have a vote, and the majority carry the day. These "officers," once appointed, rule the house and choose all minor deputies themselves. The heads alone of each house assemble at the death of the superior-general (or abbess, as she is styled in some of the more ancient orders) and choose another, equally by vote, the election being sometimes decided by only one vote. This assembly is called a "chapter." The generals of most orders reside in Rome.