What Use Is An F-call?

What use is an F-call? Names are important in day-to-day interaction between people. In amateur radio, you get issued with a callsign that after a little while takes on the role of a name. When you first become an amateur and you meet another amateur, they're likely to introduce themselves, "Hi, I'm Onno VK6FLAB". At first you do a double-take and wonder what the other person is smoking and where you can get some. After a while you realise that this is quite common. If you use your own callsign for a while, you'll get to the point where it attains the status of a name. In day to day interactions with other amateurs, you'll refer to another amateur by either their name or their callsign. You'll recognise them by either as well. It's a little like a surname, but it's different in that this particular name only makes sense among other amateurs. It gets better. After a while, you'll start hearing callsigns after the fact. Someone will say a callsign and you'll not hear it as individual letters, but