.mobi domain to be used for Desktop Browser?

Hi,

I am new but so far i have read that a .mobi should only contain files valid for mobile platforms in XHTML-MP.

But ive been reading about Device Atlas and the ability to check whether the user agent is a mobile or not-- if its not, am i allowed to redirect to a website in standard XHTML for Desktop viewing to improve user experience or would i need to give out a different URL based on a different domain?

Thanks,

Ben