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)
- 1.Reversible: Submissions are reversible.
- 2.Checked: Data entered by the user is checked for input errors and the
user is provided an opportunity to correct them. - 3.Confirmed: A mechanism is available for reviewing, confirming, and correcting
information before finalizing the submission.
Sufficient Techniques for 3.3.4 – Error Prevention (Legal, Financial, Data)
Situation A: If an application causes a legal transaction to occur, such as
making a purchase or submitting an income tax return:
- 1.G164: Providing a stated period of time after submission of the form
when the order can be updated or canceled by the user - 2.G98: Providing the ability for the user to review and correct answers
before submitting - 3.G155: Providing a checkbox in addition to a submit button
Situation B: If an action causes information to be deleted:
- 1.G99: Providing the ability to recover deleted information
- 2.G168: Requesting confirmation to continue with selected action
- 3.G155: Providing a checkbox in addition to a submit button
Situation C: If the Web page includes a testing application:
- 1.G98: Providing the ability for the user to review and correct answers
before submitting - 2.G168: Requesting confirmation to continue with selected action
Advisory Techniques for 3.3.4 – Error Prevention (Legal, Financial, Data)
- Informing the user what irreversible action is about to happen
- SCR18: Providing client-side validation and alert
(Scripting) - Placing focus in the field containing the error
- Avoiding use of the same words or letter combinations to begin each
item of a drop-down list - G199: Providing success feedback when data is submitted successfully
http://www.w3.org/TR/UNDERSTANDING-WCAG20/minimize-error-reversible.html