''Come on JEM60-lets not be too harsh. Since this IS the PROFESSIONAL pilots rumour network, I would expect most people on here would be familiar with the ICAO codes for most airports?''
Doubt it - unless they've flown in there or nominated it as an alternate. And the ICAO for ''Doncaster Sheffield Airport'' is EGCN which is what you would see on the flight plan, weather info and NOTAMs. DCA is it's IATA designation which is used more for ticketing and passenger information.
Last time I flew there it was full of red and white aeroplanes. I had no idea where DCA was.