"Thank you" or "return" pages are HTML pages that have a pre-prepared statement to front-end users who have successfully submitted a form. Before creating a new form in dotCMS it is a good idea to create a thank you/return page and record the path to the page for use in the Form Content Type (Ex: /training/thankyou.dot)
After copying the path, place/paste the path into the Form Return Page field in the Form Content Type as shown below. When the front end user submits Form Content, they will be re-directed to the "Thank You" page specified in the "Form Return Page" field on the Form Content Type.
*Please see the Form Creation documentation for complete instructions on creating a new form in dotCMS.