I recall the tale of Roger Waitout, that well-known gormless naval wireless operator bobbing up and down in one of HM Grey Funnel Lines' war canoes somewhere in the sun-soaked South Atlantic, conversing with Albert Airlines who were en-route with the long-awaited mail...
"Hello *****, this is Albert!"
"Ahhh...Roger, Wait out..."
"Hello *****, this is Albert - again!"
"Ahh...Roger. Authenticate Zulu Tango Mike" (or whatever)
"Sorry, can't - are we cleared in?"
"Ahhh….Authenticate November Delta Bravo" (or whatever)
"I authenticate DO YOU WANT YOUR BLOODY MAIL???"
"Ahhh...Roger, Albert is cleared in"