I'll have to think - I think having a box show up there would be difficult, but I have to think - in the case of a CSV import, can't be done..
So use-cases:
If the flight number ends with a letter? Adds to the flight number, not suffix?
If flight number already exists, what should it do? skip? or keep adding until there's a free one?
Route left blank? Or the route is reversed
Times - remain the same?
I guess aircraft remains the same. Since I don't care if it's used already doesn't matter much