Situation A: If a mandatory field contains no information: G83: Providing text descriptions to identify required fields that were not completed ARIA2: Identifying a required field with the aria-required property PDF5: Indicating required form controls in PDF forms Situation B: If information for a field is required to be in a specific data format: ARIA18: Using aria-alertdialog to Identify Errors G85: Providing a text description when user input falls outside the required format or values G177: Providing suggested correction text SCR18: Providing client-side validation and alert SCR32: Providing client-side validation and adding error text via the DOM PDF22: Indicating when user input falls outside the required format or values in PDF forms Situation C: Information provided by the user is required to be one of a limited set of values: ARIA18: Using aria-alertdialog to Identify Errors G84: Providing a text description when the user provides information that is not in the list of allowed values G177: Providing suggested correction text SCR18: Providing client-side validation and alert SCR32: Providing client-side validation and adding error text via the DOM PDF22: Indicating when user input falls outside the required format or values in PDF forms Advisory Techniques for Success Criterion 3.3.3 G139: Creating a mechanism that allows users to jump to errors G199: Providing success feedback when data is submitted successfully Back to top 3.3.4 Error Prevention (Legal, Financial, Data) 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: 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. Understanding 3.3.4 Show Hide techniques and failures for 3.3.4 Sufficient Advisory Failures Sufficient Techniques for Success Criterion 3.3.4 Note: Other techniques may also be sufficient if they meet the success criterion. See Understanding Techniques.