An appointment conflict happens if the following is true:
You are the participant of an existing appointment. Your availability in Display as is set to one of these values: Booked, Tentativeor Absent.
You create a new appointment. Your availability in Display as is set to one of these values: Booked, Tentativeor Absent. The new appointment is at the same time as an existing appointment.
As soon as you click on , the message Conflict detected is displayed. The appointments causing the conflict are displayed.