IE8 browser mode vs document mode
From this article on the IE8 blog, entitled How IE8 Determines Document Mode The Developer Tools settings override all Document Modes for pages displayed in a tab. The X-UA-Compatible meta tag and then header override Compatibility View Settings and the doctype unless the X-UA-Compatible value is EmulateIE7 or EmulateIE8. The user’s Compatibility View Settings override … Read more