B=North Atlantic Region
I=Reykjavik FIR (Iceland)
G=Sondrestrom FIR (Greenland)
The last two denotes the airfield, some with historical ties like BGBW=Narsarsuaq named Bluie West 1 when established during the war. Others more recent like BGAA=Aasiaat.
True, but ICAO has now run out of code combinations for Europe, which means that Pristina (Kosovo) has, bizarrely, had the code BKPR allocated to it, just to confuse those of use who use them
