Microsoft invented the MobileOptimized META tag to control the layout width for mobile markup rendered in Internet Explorer Mobile.
http://msdn.microsoft.com/en-us/library/bb159711.aspx
Mobile
Get access to data on 5,023,988 websites Mobile Optimized Customers. We know of 1,747,592 live websites using Mobile Optimized and an additional 3,276,396 sites that used Mobile Optimized historically and 878,971 websites in the United States.
Get a list of 5,023,988 websites using Mobile Optimized which includes location information, hosting data, contact details, 1,747,592 currently live websites and an additional 1,445,218 domains that redirect to sites in this list. 3,276,396 sites that used this technology previouslyand 878,971 websites in the United States currently using Mobile Optimized.
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