We'd like to implement Windows Authentication and according to the docs the first step is creating a user name in the form of "domain-name\username" so that it matches what would be found in AD. However, the cms will not let me create a user name in that form. It gives an error message stating that only certain special characters are allowed and from the list it would seem that "\" is not one of them. So, in effect, we cannot create a user name in the proper form in order to implement Windows Authentication.

Is there some configuration setting we left out to allow us to create the proper user names?