T1 is for all domestic and most European flights
T2 is for flights to Basle/Mulhouse
T3 is for flights to Capetown/Lagos and Miami
T4 is for most intercontinental flights and some European flights (AMS/Paris/Moscow/Athens/Eindhoven/Rotterdam and Tel Aviv)
So Milan flights arrive/depart at/from T1 and JFK flights are to/from T4.
[This message has been edited by mijne (edited 03-08-2001).]