What Use Is An F-call?

What use is an F-call? Some days you chew off more than you bargain for. Today I wanted to know a little more about propagation, the radio kind, not the plant variety. Four hours later I'm still reading. Everyone has an opinion, everyone's an expert and some people can even put together a coherent story on their web-site. What did I learn so-far? I didn't know that the Bureau of Meteorology has a Space Weather Branch, it's called IPS or the Ionospheric Prediction Service and their website is full of goodies. Then there's an article by Ian Poole, which appeared in the September 2002 edition of QST magazine, explaining how the Solar Flux, the K index and the A index affect your ability to talk to the other side of the world with your HF set. So, it seems that the numbers are related to things that affect each other. A high Solar Flux is good, but it's adversely affected by a high K index which in turn is represented as an average as an A index. Confused yet? So, the K index, runs between 0 and 9, 9 being a