lang="..." vs lang=""
Test passes if you see green below, and no message to ignore it.
This test is only valid if the user agent recognises html lang declarations, and :lang works.
|Ignore this test. (:lang not supported)|
Assertion: If an element contains a language attribute with an empty value, the value of a language attribute higher up the document tree will no longer be applied to the content of that element.
Red means that the formerly declared language was still inherited, despite the lang='' attribute.