Global lang-attribute validity (validity)
The global language attribute includes a valid language code such as for example, "en", "fr" or "fi" (ISO 639-1 Language Codes)
Grandfathered lang tag used:
This page uses lang="i-lux", which is a
grandfathered tag that is no longer valid under current language
tag standards. As a result, the lang value is
invalid and fails WCAG 3.1.1.
Lëtzebuerg ass e Land an Europa.