This excerpt taken from the GIS DEF 14A filed Aug 12, 2008.
Director
Retirement Policy
Non-employee directors may not stand for re-election after
reaching age 70.
Non-employee directors are expected to offer their resignation
whenever there is a material change in their principal
employment or primary occupation. The corporate governance
committee reviews the offer of resignation and recommends to the
board whether to accept it.
Company officers who are directors are expected to resign from
the board when there has been a reduction in their employment
level, position or responsibilities, or if they cease to be
employed by us.
Bet you've never seen portfolio analytics like these.