h5bp/html5-boilerplate — pull request #1502 by abhinayrathore (2014-01-30 05:58:23+00:00)
Title: Option to add alternate link to mobile website.

Websites with separate URLs for desktop and mobile websites should have an alternate link on desktop page pointing to the mobile page for SEO.
More Information:
https://developers.google.com/webmasters/smartphone-sites/details#separateurls
https://developers.google.com/webmasters/smartphone-sites/feature-phones