How can waitlists or make-ups etc be taken into account when showing the number of remaining openings?

Go to Tools > Online Web Registration > Settings and scroll down to the 'Class Search Settings' section and you can choose which conditions should be taken into consideration when the system is determining the remaining number of openings shown for new enrollees.  Set Allow Waitlist When Class Full to "Yes" and What Impacts the Number of Class Openings? Waitlist row and Makeups row to "Yes" for Online Registration and Quick Registration to have waitlists and makeups taken into account.  Remember to Save Changes.

These settings affect all online registrations - Online Web Registration, Class Listings Tables, Quick Registration, and the Parent (Customer) Portal.