A2 The hijackers bought tickets online, and used frequent-flier numbers.

There's nothing more satisfying than calling up the elite line and punching in my frequent-flier number and finding out that I have over 100,000 miles in the account.

(How does one get, as requested, a top U.N. official's personal passwords and frequent-flier number?)

Then there are their zip codes, their burglar-alarm codes and their telephone calling card numbers, not to mention their frequent-flier number.

"If later you want to know what tickets you've bought but haven't used, the airlines can't tell you that unless you have your frequent-flier number at hand."

For example, United Airlines keeps sending me a Red Carpet Club membership card with my frequent-flier number, but under the name of my husband's first wife.

State Department personnel were told to gather the credit card and frequent-flier numbers, schedules and other personal data of foreign officials.

Passengers will use ticket-boarding pass cards with the flight information and frequent-flier number printed on the front and encoded in a magnetic strip on the back.

A frequent-flier number, for example, could be used to track the travel plans of foreign officials.

Majed Moqed ordered his ticket through the same frequent-flier number, also paying for his ticket with cash in Baltimore, and sitting in seat 12A.