You can join a class waitlist during registration when the section is full.
If you try to register for a full section, Stellic will show a waitlist option (if your institution supports waitlists). Follow the prompts to join the waitlist and confirm your position. Some schools require you to actively opt in when a class is full. Details: Register for courses.
What happens next depends on your SIS:
PeopleSoft schools: if you’re first in line when a seat opens, you’re auto-enrolled.
Banner schools: you’ll get a notification (email + Stellic banner) and must accept within a limited time. If you miss it, the seat goes to the next person.
If you’re already enrolled in another course, use Drop if Enroll to try for the full course while staying enrolled in your backup; if the new course is full, you’ll be added to the waitlist and kept in your original course until you clear it. See Register for courses.