Originally Posted by
seawolf
Nowhere does US regulation require US passport must be on reservations.... The most it requires is US citizen present US passport to CBP during examination.
The verb "use' is less than helpful in
the following:
Most U.S. citizens, including dual nationals, must use a U.S. passport to enter and leave the United States.
In any event, using my US passport in a reservation means I can check in online and get a digital boarding pass!