Another option is to create Categories that are set to be a Private appointment. When establishing an Appointment Category an option will be available for a 'Private' appointment. When this option is checked for a Category details other than the Subject of an Appointment will be private to everyone else except the person who made the appointment and to those who are participating in the appointment.

Appointments that are created using these categories will make the appointment details private unless you are involved in that specific Appointment, even if you are sharing schedules with a number of other people.