Had a beauty in NZ years ago. There were 2 aircraft, one was DBC and the other EBC (they may not be their real identies). The habit from a controller was to use the last 2 letters in their callsign to give instructions. One day "
Bravo Charlie cleared for takeoff". Problem was one a/c was on Rwy 20 and the other was on Rwy 11. It was a near miss at the runway intersection.
After that it was ALWAYS the 3 letter callsign.
I later discovered the importance of always using your callsign. I had flown a particular aircraft for several months so the callsign was burnt into my brain. One day flying a different machine I kept using the brunt in callsign much to my embarrassment
and ATC annoyance. Lesson learned.