The rule does not apply if an assistant coach has language in his contract guaranteeing him the head coaching job in case of an opening. For example, this was the case when Mike Martz took over as head coach of the St. Louis Rams before the 2000 season. Also, the requirement does not apply if the assistant coach taking over the head position is a minority, as was the case with Mike Singletary and the San Francisco 49ers in late 2008.