You can add private notes to a specific person’s booking by accessing the details for your bookings directly in your calendar and clicking on the blue “Review” link provided next to booked appointments and group sign ups. Using this “Review” link gives you an administrator view of a booked Self-Book Form. In addition to providing details about an individual booking, you can also use the Details Panel to write private notes (that only you can see) about the booking, export information about the each of the booking in the “Self-Book” template, and navigate to other bookings made to that template.
In the image below you can see how the blue “Review” link will appear in your Calendar when someone has booked your Events. You can click on this link and see a pop-up dialog with the booking information that was submitted.