note about pre-authentication parameter added

src/resources/registration/resource.xml

@@ -32,5 +32,8 @@ User registration
   <property name="administrator-email"/> <!-- INFO: If 'notify-administrator' is set to true, then this property also needs to be set! -->
 
   <property name="administrator-confirmation-required" default-value="false"/> <!-- INFO: If set to true, then user only gets activated when administrator also confirms registration request -->
+
+  <!-- INFO: Also see src/resources/login/resource.xml and src/resources/redirect/resource-v1.0.1.xml -->
+  <property name="pre-auth-request-header"/> <!-- INFO: If set, e.g. 'SM_USER', then the HTTP header will be checked accordingly. Also see http://stackoverflow.com/questions/10148666/how-can-i-trust-that-the-siteminder-http-headers-havent-been-tampered-with -->
 </rtd>
 </resource>