The Strangest Tribe In History, Nuns

  In general, when a woman enters a religious order or monastery she first undergoes a period of testing life for six months to two years called a postulancy. If she, and the order, determine that she may have a vocation to the life, she receives the habit of the order (usually with some modification, normally a white veil instead of black, to distinguish her from professed members) and undertakes the novitiate, a period (that lasts one to two years) of living the life of the religious institute without yet taking vows. Upon completion of this period, she may take her initial, temporary vows