When I worked at Oracle, I noticed that the nearest (small) airport in San Carlos had the identifier code was SQL (structured query language). Cute.

I was all excited, until I found out that they "explained" Canadian airport codes by saying they appropriated all the Y-initial ones. Doesn't make YUL or YYC or YYZ seem more reasonable (YML YCG YTO?).

At least now I understand EWR.

YTO is actually the Toronto metropolitan code, like they described for Washington and New York, although it doesn't seem to get much use (since all it'll do is give you the option of arriving or departing at Toronto City Centre or, uh, I think an airport in Buttonville, wherever that is.)
But that doesn't really explain YYZ or YYC etc. and I can't find any explanations on google, just a lot of wondering.

To make this sort of linguistic, it's strange to me that my natural inclination is to say 'why why zee' instead of 'why why zed'. I think because the former flows better. Or maybe I'm slowly becoming American! Uh oh.

I find the Canadian Y-based airport codes really annoying. VAN is some tiny airport in Turkey!

As a matter of fact, mpw that you mention it (and I google it), it's the airport of Van, which gives the lie to the "fact" I just saw somewhere that EEK is the only code identical to the name of its town.

My favourite code is for Madrid's Barajas airport (MAD). Very fitting.

Canadian cities served by more than one airport also have "city codes": YTO for Toronto (YYZ Pearson, YKZ Buttonville and YBZ Toronto Centre airports) and YMQ for Montreal (YUL Turdeau (Dorval) and YMX Mirabel).