Pre-fill rejected Workflows responses enables users who have had their response to a Workflow rejected by an approver to complete the workflow a subsequent time, more quickly.
By default, this is available to any user who has completed a workflow that has then been rejected by an approver.
When an approver selects to 'Reject' a workflows response, you will be given the option to include a message as to why the response was rejected. This will be included in an email (such as the one below).
The user will be given the option to 'View My Response'. After clicking this they will be navigated to their response and given the option to 'Resubmit Now' and rectify any issues in the workflow, with all their previously provided details pre-filled.
For more information on the Approval and Rejection process for Workflows, please read this article.