QFA10 Syndrome (also affects Speedbird).
"Qantas Ten, climb to flight level 390"
"Qantas
One Zero, flight level 390"
Ok, I can take a hint,
"Qantas One Zero, contact centre on 123.45"
"Qantas
Ten roger, 123.45"
Still, if thats the worst that happens on a shift its been a good day.