How to. Mandatory techniques

If a form contains fields for which information from the user is mandatory.

• Provide text descriptions to identify required fields that were not completed
• Provide client-side validation and alert

If information provided by the user is required to be in a specific data format or of certain values.

• Provide a text description when the user provides information that is not in the list of allowed values
• Provide a text description when user input falls outside the required format or values
• Provide client-side validation and alert
• Provide client-side validation and adding error text via the DOM

Additional, Advisory Techniques

• Create a mechanism that allows users to jump to errors
• Validate form submissions on the server
• Re-display a form with a summary of errors
• Provide error notification as the user enters information
• Assist the user in making corrections by providing links to each error
• Highlight or visually emphasize errors where they occur
• Complement text with non-text content when reporting errors
• Provide success feedback when data is submitted successfully

How to. Mandatory techniques

• Provide descriptive labels and one of this techniques
  • Provide expected data format and example
  • Provide text instructions at the beginning of a form or set of fields that describes the necessary input
  • Place labels to maximize predictability of relationships
  • Provide text descriptions to identify required fields that were not completed
• Use label elements to associate text labels with form controls
• Provide a description for groups of form controls using fieldset and legend elements
• Use the title attribute to identify form controls when the label element cannot be used
• Use an adjacent button to label the purpose of a field

Additional, Advisory Techniques

• Describe what will happen before a change to a form control that causes a change of context to occur is made
• Use Accessible Rich Internet Application describedby property to provide a descriptive, programmatically determined label
• Use Accessible Rich Internet Applications to programmatically identify form fields as required
• Provide linear form design and grouping similar items

How to. Mandatory techniques

If a mandatory field contains no information

• Provide text descriptions to identify required fields that were not completed

If information for a field is required to be in a specific data format

• Provide a text description when user input falls outside the required format or values
• Provide suggested correction text
• Provide client-side validation and alert
• Provide client-side validation and adding error text via the DOM

Information provided by the user is required to be one of a limited set of values

• Provide a text description when the user provides information that is not in the list of allowed values
• Provide suggested correction text
• Provide client-side validation and alert
• Provide client-side validation and adding error text via the DOM

Additional, Advisory Techniques

• Create a mechanism that allows users to jump to errors
• Make error messages easy to understand and distinguishable from other text in the Web page
• Validate form submissions on the server
• When mandatory information has not been provided, including descriptions or examples of correct information in addition to identifying the field as mandatory
• Repeat and emphasize suggestions for correcting each input error in the context of its form field
• Provide a way for the user to skip from each item in a list of suggestions to its corresponding form field
• Provide additional contextual help for the form field requiring change
• Accept input data in a variety of formats
• Provide success feedback when data is submitted successfully
• Provide a text description that contains information about the number of input errors, suggestions for corrections to each item, and instructions on how to proceed
• Provide a text description that contains suggestions for correction as the first item (or one of the first items) of content, or emphasizing this information in the content
• Display errors and suggestions in the context of the original form (for example, re-displaying a form where input errors and suggestions for correction are highlighted and displayed in the context of the original form)
• Provide “correct examples” for data and data formats as initial text in mandatory form fields
• Provide links to suggested correction text “close to” form fields, or providing the suggested correction text itself directly on the Web page “next to” form fields
• Provide client-side validation and alert
• Provide client-side validation and adding error text via the DOM
• Call a function from the submit action of a form to perform client side validation
• Identify required fields with the “required” property
• Identify valid range information with the “valuemin” and “valuemax” properties

How to. Mandatory techniques

If an application causes a legal transaction to occur, such as making a purchase or submitting an income tax return

• Provide a stated period of time after submission of the form when the order can be updated or canceled by the user
• Provide the ability for the user to review and correct answers before submitting
• Provide a checkbox in addition to a submit button

If an action causes information to be deleted:

• Provide the ability to recover deleted information
• Request confirmation to continue with selected action
• Provide a checkbox in addition to a submit button

If the Web page includes a testing application

• Provide the ability for the user to review and correct answers before submitting
• Request confirmation to continue with selected action

Additional, Advisory Techniques

• Tell the user what irreversible action is about to happen
• Provide client-side validation and alert
• Place focus in the field containing the error
• Avoid use of the same words or letter combinations to begin each item of a drop-down list
• Provide success feedback when data is submitted successfully

How to. Mandatory techniques

If a form requires text input

• Provide a help link on every Web page
• Provide help by an assistant in the Web page
• Provide spell checking and suggestions for text input
• Provide text instructions at the beginning of a form or set of fields that describes the necessary input

If a form requires text input in an expected data format

• Provide expected data format and example
• Provide text instructions at the beginning of a form or set of fields that describes the necessary input

Additional, Advisory Techniques

• Use the title attribute to provide context-sensitive help
• Checking byte of character and auto-converting to expected byte for text input if applicable

How to. Mandatory techniques

• Follow the mandatory techniques for Success Criterion 3.3.4 for all forms that require the user to submit information