Originally Posted by
Adam1222
Right, I agree that is what they are doing, but I'm confirming that it's a glitch on Delta's end to display as "First Class", not a glitch on KLM's end.
Yes, that would look to be a glitch. DL used to use P/A/G booking classes for domestic FC fares before converting those fares to J/C/D/I/Z classes (leaving P/A/G only for PE fares). I'm guessing it might be a hangover from those days.