[Butch Cassidy Slept Here]

With regard to PHX's post #10: The rule as to who the gate agent will, and will not, allow to board is EQUALLY vague. The Contract of Carriage for American Air, and other carriers, basically, allows the gate agent to deny a customer boarding on a whim. If a given customer, truly, presents a clear and present danger to the aircraft; its crew; and/or the passengers, then a review of a gate agent's decision should be upheld if a "second opinion" was required from another employee of the same airline.