By default IE8 displays web content using its newest, most standards compliant mode. The problem is that some of today’s web pages expect the older, less interoperable behavior from Internet Explorer , handing this latest version of Internet Explorer code meant for older releases of the browser. The result is web pages that might not function correctly in ways ranging from just looking a bit misaligned to not working at all. During the Beta cycle, the Compatibility View button, which allowed savvy end-users to resolve compatibility problems they might encounter as described above. Microsoft has combined telemetry data about Compatibility View button presses with other feedback sources – customer-filed bugs, Report a Webpage Problem data, their wn compatibility testing, etc… – to create a list of sites that were likely best displayed in Compatibility View. The list’s not enabled by default – users must opt-in to the feature (known as the Compatibility View List or Compatibility List, in other documents) as part of the first run experience or later by selecting ‘Include updated website lists from Microsoft’ at Tools -> Compatibility View Settings. For those that chose to do so, IE8 displays sites on the list in Compatibility View rather than the default “best standards mode” i.e. it’s as if the user pressed the Compatibility View button for sites on the list with the benefit that the end user avoids having to first experience a website compatibility failure to make the determination that these particular sites are best viewed in a non-default manner.
Typing ‘res://iecompat.dll/iecompatdata.xml’ into the browser’s address bar shows the list currently available on your IE installation.
With the next Compatibility View List update you’ll see a new designation for site removal in the tracking spreadsheet – “Removed per Microsoft testing” – indicating that test passes have not found a compatibility issue for some time and so Microsoft are removing that site from the Compatibility View List.