This excerpt taken from the ALL DEF 14A filed Apr 2, 2008.
Executive Sessions of the Board and Presiding Director
The independent directors meet in regularly scheduled executive sessions without management. When meeting in executive sessions, the presiding director is determined by the subject matter of the session. If the subject is within the scope of authority of one of the standing committees, the chair of that committee acts as presiding director over the executive session. Directors who are not committee chairs are appointed on a rotating basis to act as presiding director over executive sessions that do not fall within the subject scope of one of the standing committees. The Board believes this practice provides for leadership at all executive sessions without the need to designate a single presiding director and it also provides an opportunity for each director to assume the role of presiding director from time to time.