If an input error is automatically detected and suggestions for correction are known, then the suggestions are provided to the user, unless it would jeopardize the security or purpose of the content. (Level AA)
For Web pages that cause legal commitments or financial transactions for the user to occur, that modify or delete user-controllable data in data storage systems, or that submit user test responses, at least one of the following is true: (Level AA)
Reversible: Submissions are reversible
Checked: Data entered by the user is checked for input errors and the user is provided an opportunity to correct them.
Confirmed: A mechanism is available for reviewing, confirming, and correcting information before finalizing the submission.