Quick tip: you can’t include a backslash in the name of the SharePoint 2010 Content Type. In fact, there are several illegal characters: \ / : * ? " # % < > { } | ~ & , two consecutive periods (..), or special characters such as a tab. What, you didn’t know that after entering one of these characters in the name? Is it because you saw this screen: Oh, that’s right….you need to turn off custom errors in the layouts folder…See this blog post for details and you’ll also need to turn off for ......