This excerpt taken from the SIRI DEF 14A filed Apr 21, 2006.
The Committee shall meet at least two times annually, or more frequently as circumstances dictate. The Chairman of the Board of Directors or any member of the Committee may call meetings of the Committee. All meetings of the Committee may be held telephonically.
All non-management directors that are not members of the Committee may attend meetings of the Committee but may not vote. Additionally, the Committee may invite to its meetings any director, members of management of the corporation and such other persons as it deems appropriate in order to carry out its responsibilities. The Committee may also exclude from its meetings any persons (other than Committee members) it deems appropriate in order to carry out its responsibilities.