Appointments set within EBSuite has always sent appointment notices to Users when Users were added as Attendees to an appointment. References were added to an appointment to keep track of the related entity to the appointment.
Now when an appointment is created, the user may add not only Refereneces, but Team Mates (previously this was known as Attendees) as well. When the user adds a "Team Mate" to the appointment that Team Mate will receive an appointment notification to the email address of record.
What is new is the capability to add a Contact from the database as a "Team Mate".
Care should be taken to use appropriate verbage in the email if the Contact is included as a Team Mate, because their notification is exactly the same as that of an internal user.