Is 'en-EU' a valid value for HTML 'lang' attribute?
Markup for different editions of my news site... US Edition: <html lang="en-US" xml:lang="en-US"> ... </html> India Edition: <html lang="en-IN" xml:lang="en-IN"> ... </html> Europe Edition (in this case not a specific country, i.e. news covers a broader region): <html lang="en-EU" xml:lang="en-EU"> ... </html> I am depending on the markup of the page to make the target language/region of pages clear to the search engines because the different editions of the news site use a directory-based path (e.g. example.com/eu/ ) rather than a sub-domain ( eu.example.com ) or domain (e.g. example.eu )