Detect IE8 Compatibility Mode

I have recently had a client who complained to me that the site was broken in IE8 even though I had already checked it out. It turns out the issue was M$'s great "Compatibility Mode"

I know my way around CSS well enough but it felt wrong making any changes to keep this IE only mode happy when all other browsers were not complaining. Bing! I had an idea and went to Google and found this document on Defining Document Compatibility.

Turns out I can force the users browser to IE8 mode with the following

Hopefully this will help some other developer with their designing woes.