[lang="en-GB"], lang="en-US"

Ignore this test. (lang= with lang attribute is not supported)
You can only get meaningful results for this test if the lang= selector works with the lang attribute, since it checks a detail with regard to that support.

Test passes if you see green below.

Text

Assertion: A lang= value and a lang attribute value will not match if their region subtags differ.

Next test
HTML5

selectors-041
Result summary & related tests