A bishop is the president of the Aaronic priesthood in his ward (and is thus a form of Mormon Kohen; in fact, a literal descendant of Aaron has "legal right" to act as a bishop after being found worthy and ordained by the First Presidency). In the absence of a literal descendant of Aaron, a high priest in the Melchizedek priesthood is called to be a bishop. Each bishop is selected from resident members of the ward by the stake presidency with approval of the First Presidency, and chooses two "counselors" to form a "bishopric". In special circumstances (such as a ward consisting entirely of young university students), a bishop may be chosen from outside the ward. A bishop is typically released after about five years and a new bishop is called to the position. Although the former bishop is released from his duties, he continues to hold the Aaronic priesthood office of bishop. Church members frequently refer to a former bishop as "Bishop" as a sign of respect and affection.