Registering for Classes When You Know the CRN For instructions on how to access the self-registration page, please visit the guide  here.  Registering for a class when you know the CRN (course reference number) The CRN is a unique 5-digit number assigned to each specific section of a course. You can find course CRNs for Online specific programs here   1. To register for a class when you know the CRN, use the tab that says "Enter CRNs". 2. Type the 5-digit CRN into the designated box.  3. Click "Add to Summary", then click "submit" to save the changes.