Honestly, I thought I covered this on Friday based on a post by Google's Pierre Far but he went again and posted a new post on Google+ referencing a blog post he published this morning on the Google Webmaster Blog on a new hreflang tag. The post on Friday was about using the rel-alternate-hreflang across domains. Today's post is about different home pages that use the Accept-Language HTTP header.
In short, Google and Yandex support a new tag for sites that are multinational and multilingual websites and redirect or change the content of the pages for those users. This new tag helps Google and Yandex understand those redirects and content.
How does this work? Well, the example Pierre gave includes the following URL scenario:
- http://example.com/en-gb: For English-speaking users in the UK
- http://example.com/en-us: For English-speaking users in the USA
- http://example.com/en-au: For English-speaking users in Australia
- http://example.com/: The homepage shows users a country selector and is the default page for users worldwide
The code you would use on these pages include:
For more details see the Google blog post.
Forum discussion at Google+ and WebmasterWorld.