ICAO
If I remember correctly:
C=Canada
Y=Yes (as in Yes Wx is available for the station) This comes from way back...
Canada used 2 letter identifiers to identify weather reporting stations. Those 2 letter codes then had either "Y" or "W" added in front of them. Y meant they were co-located with an airport. Or "Y"es there is an airport there too. Or it is a weather station "W"ithout and airport for those that had the W in front.
They changed the last letter to "X" if the code was already in use by another city. And changed it to "Z" if the code was already in use by a U.S. airport.