People can be cruel with callsigns - there was a chap in the RAF many years ago who had a slight stammer and struggled with words beginning with F - he was given the callsign of 44Foxtrot on the Tac net. FFFFFFFFFF........
Thread drift sorry, but we used to amuse ourselves with our storeman from the west-country who had particularly broad accent, 'Th' sounds came out as 'F'. When we had to cost a job he held all of the prices in a paper log.
So we'd pick a list of things with '3's in them and go ask him - "It's Firteen pounds and Firty Free' came the answer. And then 10mins later another engineer would go by with the same list. Ah children can be cruel.