[HCDX]: Quebec = PQ or QC?

[Mauno Ritola <ritola@xxxxxxxxxxx>]

I have seen these two abbreviations (PQ and QC) used for the province of
Quebec. 
Which one is the official one or should they both be used depending on the
purpose (postal/others)?

73, Mauno
------------------------------------------------------------------------
This is a message from Mauno Ritola <ritola@xxxxxxxxxxx>
to hard-core-dx@xxxxxxxxxx list. To unsubscribe the list, send
"unsubscribe hard-core-dx" in mail body to majordomo@xxxxxxxxxxx
For more information, please check http://www.iki.fi/rko/hard-core-dx/
or email Risto Kotalampi, rko@xxxxxxx
------------------------------------------------------------------------