Yes ASO is used by many of our members when online. The number you use is up to you. General rule I follow is if I fly any event or ASHA flights online I use "Air Source" as my callsign along with my AS number. Whenever I fly any Bid Div weekly contracts, or any Schedule Division flights, I use the callsign and flight number for the airline i'm flying. Entirely up to you as there is no specific direction for online flying