When deleting a registration form question that has already been answered, you will be prompted that data for this question will be hidden. To keep the data but make a question nonexistent to participants, follow these steps for making a registration form question internal.
 
  1. Under season name, click Setup
  2. Under Settings menu choose Registration forms
  3. Click Customize registration form
  4. Scroll to desired question, click Edit
  5. Click Advanced settings
  6. For position, choose Internal
  7. Click Apply
  8. At bottom of page, click Save and continue