Bulk Student Registration and Private class option
If you make a class private (uncheck the Include in the online class catalog box on the class details page) a "bulk registration" link will show up in the class edit screen. You can use this link for bulk registering students or provide the link to a group client to enter their students. No payment process is involved in the bulk registration.
Look at the bulk registration system simply as a way to manage the names on the roster and is typically used for group registration. All other processes (payment, notification, etc.) happen manually through the virtual terminal or edit the payment request for each student.
Making a class private will remove that class from appearing on the registration page.
Once the class is private you will see Glass/Sunglasses shown next to it.