Microsoft today announced that they are adding new functionality to Enterprise Mode for Internet Explorer 11 as part of the November update. In addition to the existing Enterprise Mode Site List which helps in web app compatibility issues, a new docMode section of the list enables IT to specify the document mode in which a specific Web site should load, without changing the website code. This new feature will help enterprises stay up to date regardless of the version of IE currently running in their environment.
How it works?
The enhanced enterprise site list enables organizations to maintain compatibility with legacy and orphaned Web apps by specifying a document mode in a central list. Sites that are already on the enterprise site list are not affected by the enhancement, and will continue to load in Enterprise Mode as usual. The enhanced site list has the same ability to selectively target Web sites as before. For example, www.contoso.com/travel can be set to use Enterprise Mode, while www.contoso.com/erp may be set to use IE9 document mode.
When Internet Explorer 11 navigates to a site on the list, the browser loads the page in the specified document mode just as it would load the page if the document mode were specified through an X-UA-Compatible meta tag on the page, and the UA string associated with the selected document mode is sent. Some customers have told us that they even need to override the X-UA-Compatible meta tag as set by the Web site, so this new functionality does so without needing to change a single line of code on the site itself.
Read more about it from the link below.
Source: IE Blog