Our KLM flight this summer goes from AMS to Nairobi and carries a NW code share flight number. The return flight, which is simply the turnaround...same aircraft back to AMS is KLM designated only.

It's the only part of our long itinerary that doesn't have a NW flight number and as you can't rulebust on KLM it has caused us no end of grief. A supervisor ultimately intervened, but I'm curious why the flight outbound would code share, but wouldn't on the return.