. _:vb17347053 . _:vb17347052 _:vb17347053 . "boarding policy" . . _:vb17347051 . "The type of boarding policy used by the airline (e.g. zone-based or group-based)." . _:vb17347053 . _:vb17347052 . _:vb17347051 . _:vb17347051 _:vb17347052 .