In HTML, there is a very simple way to advertise a relationship between a desktop web page (or site) and the equivalent page (or site) on the mobile web. Very few desktop web sites implement this practice today. I have no idea why not, because the change is trivial and the benefits are broad.
Use link relationships to express that a particular web page is the mobile equivalent of a desktop web page. Link relationships can also be used to express that a mobile web site is the mobile equivalent of a desktop web site.
Link to Mobile Version using HTML Link Tag
Here is an example HTML link tag embedded in the header of a desktop web page to declare a relationship with a mobile web page:
<link rel="alternate" media="handheld" href="http://m.example.com" />
- The href expresses a page-to-page relationship when its target is the exact equivalent mobile web page, i.e. a mobilized version of a news article.
- The href expresses a site-to-site relationship when its target is the entry point of the related mobile web site, as in the sample.
An added benefit of using link relationships for mobile web discovery is improved mobile SEO. Desktop web crawlers look for HTML link tags to define page relationships. The crawler obtains the mobile web URL from the href attribute and knows from the media attribute that the content is mobile-friendly.
There are two other easy ways to increase mobile web discovery. These approaches are effective for mobile site discovery but don’t express direct relationships between a desktop web document and its counterpart mobile web document.
List Mobile Web URLs in a Google Mobile Sitemap
Use a Google Mobile Sitemap. A Google Mobile Sitemap is a sitemap file containing only mobile web URLs. The sitemap uses an additional XML namespace and a new tag to declare a URL as mobile content. Advertise your mobile sitemap in /robots.txt or submit it directly to search engines using webmaster portals.
Here is an example Google Mobile Sitemap:
<?xml version="1.0" encoding="UTF-8" ?>
Specify Mobile and Desktop Entry Points in Meta.txt
Use a /meta.txt file in the root directory to define PC and mobile entry points (and other metadata) for the website.
Here is an example of a meta.txt file that would be found at http://example.com/meta.txt:
description: example.com is a widely used example website
keywords: example, demo, demonstration