Understanding Identify Common Purpose


This section contains the main explanatory content of the Understanding. It explains why the Guideline or Success Criterion exists and, at a high level, how to meet it.

The intent of this success criterion is to allow more support for user preferences and for user needs. Extra support such as familiar terms and symbols are needed for many users to be able to the web. If a user agent knows what a control does then the user agent can provide the extra support.

This success criteria requires the author to add the context of common buttons, links and field so that user agents knows what they do and can add extra support. It is similar to adding role information (as required by 4.2.1) but instead of providing information about what the UI component is (such as a button) it provides information about what the action does (such as opening a help page).

For example when a browser knows that a field is expecting the user’s name, the autocomplete function can work. This is particularly useful for users with disabilities makes remembering or copying information harder, and for users who make spelling mistakes or are likely to missread the label. This extra support prevents the user from making mistakes and makes it much easier for them to fill out forms.

In another example, a toolbar or browser extension can add symbols to common links and functions that are familiar to the user. What is familiar for some users may not be familiar to other users, requiring them to learn new symbols. This success criteria enables personalization, such as loading a set of symbols that is appropriate for the specific user, ensuring that all users find the icons simple and familiar.

In another example, browser extensions can add context sensitive help for known controls. Purpose of controls may also benefit speech users who rely on accessible names. For requirements related to Accessible Name, refer to Success Criterion 2.4.12

Meeting the success criteria

Common ways to meet this success criteria include:

Providing the purpose of a control using autocomplete - these techniques work on all the common fields.

Providing purpose of Controls using ARIA - these techniques work on all the controls but is not yet a stable specification.

Purpose of Controls using Microdata and the ARIA vocabulary - these techniques work on all the controls but is not yet a stable specification.

Purpose of Controls using schema.org - these techniques work on the following items:

++Add John’s Table++

Autocomplete notation is as follows:

Values for autocomplete
Value Description
name full name
honorific-prefix prefix or title (Mr., Mrs. Dr., etc.)
given-name given or first name
additional-name additional or middle name
additional-name-initial additional or middle name initial
family-name family name, surname, or last name
honorific-suffix suffix (Jr., II, etc.)
nickname nickname
street-address full street address condensed into one line
address-line1 first line of street address
address-line2 second line of street address
address-line3 third line of street address
city locality or city
area administrative area, state, province, or region
postalcode postal or ZIP code
country country name
fax full fax number, including country code
fax-country-code international country code
fax-national national fax number: full number minus country code
fax-area-code area code
fax-local local fax number: full number minus country and area codes
fax-extension fax extension number
email email address
tel full phone number, including country code
tel-country-code international country code
tel-national national phone number: full number minus country code
tel-area-code area code
tel-local local phone number: full number minus country and area codes
tel-extension phone extension number
cc-name full name, as it appears on credit card
cc-number credit card number
cc-exp-month month of expiration of credit card
cc-exp-year year of expiration of credit card
cc-exp date of expiration of credit card
cc-csc credit card security code
language preferred language
bday birthday
bday-year year of birthday
bday-month month of birthday
bday-day day of birthday
topic Topic for the form. Typically selected from a list of reserved words
comment comment section. Typically a free text field
subject form subject. Typically a free text field
answer answer to a section question
org company or organization
organization-title user's position or title within company or organization
sex sex or gender
gender gender identity
url Website URL
photo photo or avatar
section-***** used to group forms together


This explains how following the success criterion benefits particular types of users with disabilities.

Following the success criterion benefits users with particular types of, or a combination between, these disabilities in multiple ways:

This success criterion benefits people with many different cognitive disabilities including people with language related disabilities memory related disabilities and disabilities that affects executive function and decision making. It provideds extra support such as:

When metadata for common input controls is provided:


For example a person growing older may find that their ability to learn new things has slowed down. This includes learning new interfaces, symbols, and designs. They may also rely on tool tips. So long as the design is one they know they can use the application and stay in the work force. When interfaces change, they may try to learn the new interface, but the cognitive load becomes too great and they need to retire. Having familiar icons and buttons can help the user work for longer.



This section references techniques that can be used to meet the Guideline or Success Criterion. There are sub-sections for sufficient techniques, advisory techniques, and failures.

Remove any parts of the template that are not used, such as the section and heading for situations, sub-lists of techniques, or the "AND" construction. Also remove the square brackets around placeholder optional components.


Techniques that are sufficient to meet the Guideline or Success Criterion.


Techniques that are not sufficient by themselves to meet the Guideline or Success Criterion.

Same template as sufficient techniques.


Techniques that document conditions that would cause the page not to meet the Guideline or Success Criterion, even if sufficient techniques are also used.

Same template as sufficient techniques.