Should airline booking codes be secret?

Flying Blue, the frequent-flier program of Air France/KLM, has banned customer service agents from revealing the codes the airlines use when booking awards or upgrades. If you ask them, they will tell you it’s none of your business. Is this misplaced paranoia or do carriers have the right to keep that information secret?

For smart and sophisticated travelers, the importance of having access to raw airline data cannot be overstated. Benefiting from that access has changed my travel life — it has ensured that I always pay the lowest possible fares and fly in comfort and luxury at the same time. Booking codes, of course, use letters of the alphabet…