Originally Posted by gary_nj
Yes, the first letter is the fare basis code.
Quick question: The itinerary you are talking about here:
DEN-SLC-LAX-ICN-SIN...
the whole thing is showing as Delta fare basis M?
If you use the ITA tool, it might be interesting to see what corresponding fare basis is being shown for the ICN-SIN segment that has a KE flight number...
The ICN-SIN flight is KE 641 (no DL codeshare). I found this fare on Orbitz.
When I looked at the fare code for the DEN-SLC-LAX-ICN-SIN and back on Orbitz, it only gave 2 fare codes. Both fare codes are in M fare class.