Domanda 287, Air Law - ATPL - Airline Transport Pilot license

May ask an aircraft to temporarily change its call sign for safety reasons when there is a risk of confusion between two or more similar call signs.
Must not ask an aircraft to change its call sign.
May require to change the call sign for safety reasons when there is a risk of confusion between two or more similar call signs providing the aircraft is on a repetitive flight plan.
May not ask an aircraft to change its call sign after accepting the flight plan.