The X-UA-Compatible meta tag allows web authors to choose what version of Internet Explorer the page should be rendered as.

Here are your options:

"IE=edge"
"IE=10"
"IE=EmulateIE10"
"IE=9"
"IE=EmulateIE9
"IE=8"
"IE=EmulateIE8"
"IE=7"
"IE=EmulateIE7"
"IE=5"