Marking a meeting or appointment private can hide some of the meeting details from others in your organization.
Important: Even if you share and grant Read permissions to your calendar to another user, they will not be able to see the details of your private appointments.
If you share and grant Delegate with access to view private items permissions, those delegates will be able to view details of your private appointments. By default, delegates do not have access to private items, but you can change this option when assigning Delegate permissions.
Sharing your folders and assigning permissions must be done explicitly. To share a folder, see Share an Outlook calendar with other people.
Create or open the appointment or meeting that you want to make private.
On the Meeting or Appointment tab, click Private.
Save or send your meeting or appointment as usual. Any meeting attendees will be able to see the details of the meeting.