HTML page has lang attribute

Accessibility Requirements Mapping

3.1.1 Language of Page (Level A)

Required for conformance to WCAG 2.0 and later on level A and higher
Outcome mapping:
- Any failed outcomes: success criterion is not satisfied
- All passed outcomes: success criterion needs further testing
- An inapplicable outcome: success criterion needs further testing
H57: Using language attributes on the html element
- Not required to conformance to any W3C accessibility recommendation.
- Outcome mapping:
  - Any failed outcomes: technique is not satisfied
  - All passed outcomes: technique needs further testing
  - An inapplicable outcome: technique needs further testing

Applicability

This rule applies to any document element if it is an html element that:

is in a top-level browsing context; and
has a node document with a content type of text/html.

Note: html elements within iframe and object elements are not applicable as iframe and object elements create nested browsing contexts. However, as these elements are meant to provide a layer of isolation, the declared language of their parent browsing context will likely not be inherited, making it possible for empty lang attributes in nested browsing contexts to also cause accessibility issues.

Expectation

Each test target has a lang attribute that is neither empty ("") nor only ASCII whitespace.

Assumptions

The language of the page can be set by other methods than the lang attribute, for example using HTTP headers or the meta element. These methods are not supported by all assistive technologies. This rule assumes that these other methods are insufficient to satisfying Success Criterion 3.1.1: Language of Page.

Accessibility Support

There are no major accessibility support issues known for this rule.

Background

Test Cases

Passed

Passed Example 1

This html element has a lang attribute with a non-empty ("") value.

<html lang="en"></html>

Failed

Failed Example 1

This html element does not have a lang attribute.

<html></html>

Failed Example 2

This html element has a lang attribute with an empty ("") value.

<html lang=""></html>

Failed Example 3

This html element has a lang attribute whose value is only ASCII whitespace.

<html lang=" "></html>

Failed Example 4

This html element has no lang attribute, only a xml:lang attribute.

<html xml:lang="en"></html>

Inapplicable

Inapplicable Example 1

This rule does not apply to svg element.

<svg xmlns="http://www.w3.org/2000/svg"></svg>

Inapplicable Example 2

This rule does not apply to math element.

<math></math>

Acknowledgements

This rule was written in the ACT Rules community group, with the support of the EU-funded WAI-Tools Project.

Authors

Jey Nandakumar

Previous Authors

Annika Nietzio

Changelog

This is the first version of this ACT rule.