Hi Mozzers,

I have a question about the rel="alternate" hreflang tag, with an example.

When I use two subfolders for two different countries/languages, for instance www.domain.com/nl-nl/ and www.domain.com/nl-en/ (for the English version) and I want to use the rel="alternate" hreflang tag, do I need to follow the ISO standards concerning Uppercase country code and Lowercase language code (en-NL)? Or is it okay to use the Lowercase country and language code (en-nl), since we also use this in the URL of the Subfolder.

What does Google prefer?

Thanks in advance.