QR, QR, QR!!! QR is the airline code for Qatar Airways. Period! QA is the two-letter airline designation code for a regional carrier affiliated with Mexicana. You wouldn't say that Lufthansa is LA, would you? Or that Oman Air is OA (it's Olympic)? Nor would you call the airport in Doha DIA since that is Denver's designation. Let's be precise here so we don't end up in Tampico! (And yes, weirder things have happened.) Can you tell this is a pet peeve of mine?
Mandi