Originally Posted by ZKOKA

In my experience it is fine to have only your given name on the ticket, as long as all names are included in the secure flight data. I have a first and second name, the second name is my "given" name (a concept that used to be quite common in Germany). I always book my tickets with my second name only and enter both names in the secure flight data, or have the airline enter it there. I travel to the US once or twice a year and have never had a problem. Even if you forget to enter one of your first/given names this can still be updated during check-in.