- Stop the iCal service on the server.
- Run the following command in a Terminal window. You will be prompted to enter an administrator's password.
sudo serveradmin set calendar:EnablePrivateEvents = yes
- Start the iCal service on the server.
- Quit and re-open iCal on each client.
iCal users with Mac OS X 10.5.3 or later should now see the option to make an event private when creating it in a server-hosted calendar.