The .MOBI TLD has three mandatory technical requirements:
- To ensure premium usability on mobile devices, the home page of your site must be coded in valid XHTML Mobile Profile.
- .MOBI sites must implement a page at the second level domain. This is to eliminate the need to type in "www" when browsing .MOBI sites from a mobile device. For example, both www.mydomainname.mobi and to mydomainname.mobi.
- The home page of your site must not use frames.
A complete list of .MOBI website requirements and recommended best practices is available here: .MOBI Domain Compliance.