Anyone care to explain what this business of having a 'international diversion agreement' actually is? I have never heard of it and it makes no sense for anyone to have any agreement to land at a publicly accessible airport . What does it matter if you land as an emergency/diversion/charter/RPT? The operator of the aircraft is responsible for ground handling not the airport, so what is it to them how you get there? And even if they get swamped in a 9-11 type mass diversion what does it matter? You wait in line until there is a parking available. No wonder QF didn't have one I personally don't see what purpose it actually serves.