1. Navigate to Communities > Special Events > Friends Asking Friends > Kinterathon.
  2. Hover over the event name and select Website Info.
  3. Click on Customize Forms.
  4. Click "Select" next to the appropriate form.
  5. Click through to the appropriate field category (Standard Profile Fields, Custom Profile Fields, etc.).
  6. Mark the "Require" radio button for each desired field
  7. Click Save & Done.
  8. Return to Website Info and click Publish This Event Now.
Alternatively if a field is currently required and your organization would rather like for it to be optional but still available to fill out, refer to KB 59401.