--- a/configmix/config.py	Thu Mar 10 10:42:55 2016 +0100
+++ b/configmix/config.py	Thu Mar 10 10:45:09 2016 +0100
@@ -41,6 +41,14 @@
 
 class Configuration(_AttributeDict):
 
+    """The configuration dictionary with attribute support or
+    variable substitution.
+
+    .. note:: When retriving by attribute names variables will *not*
+              substituted.
+
+    """
+
     def getvar(self, varname, default=_MARKER):
         """Get a variable of the form ``[[ns1.]ns2.]name`` - including
         variables from other namespaces.