and what the feature ''Multi-platform setting'' in ''Network options'' do?
In the past, it was possible to go online with a PS2 (Playstation 2) and play PES6 with your friends. BUT, you could only play in special PS2 lobbys, in fact the players were split into the PC lobby players and the PS2 lobby players. (PC players couldn't join the PS2 ones and the other way around)
The only place where they could start a match against each other was the *friendly* lobby, where matches didn't count for the statistics.
I don't know the reason, but even joining that lobby wasn't possible
without activating the multi-platform option in the network options first. So in order to play vs. PS2 players as a PC player you had to activate that option and then join the friendly lobby. That option doesn't have a purpose now, I think Elpinfi also didn't program it. You can try going online with a console, no one has tested that yet as far as I recall.