Required Text. Specifies the content type name. The value can be a reference to a resource in the format $Resources:String. ...

Required Text. Specifies the content type name. The value can be a reference to a resource in the format $Resources:String. The name itself cannot be longer than 128 characters and cannot contain the characters \ / : * ? " # % < > { } | ~ , two consecutive periods (..), or special characters such as a tab. 
An error occurs if another content type with the same name exists in the collection where the content type is added.