By default, no priority is defined for new appointments. However, you can set low or high priority to them. Once priority has been defined, indicative icons appear on the top left corner of appointment badges.
Define appointment priority
Use one of the following methods to define appointment priority.
From the Calendar, right-click on the appointment badge and select High priority or Low priority.
From the Appointment window, select High priority or Low priority.
Cancel appointment priority
To cancel appointment priority, in the Appointment window, deselect High priority or Low priority.