diff --git a/wallace/module_invitationpolicy.py b/wallace/module_invitationpolicy.py
--- a/wallace/module_invitationpolicy.py
+++ b/wallace/module_invitationpolicy.py
@@ -1274,6 +1274,9 @@
         else:
             message_text += " " + _("The copy in your calendar has been marked as cancelled accordingly.")
 
+    if object.get_recurrence_id():
+        message_text += "\n" + _("NOTE: This cancellation only refers to this single occurrence!")
+
     message_text += "\n\n" + _("*** This is an automated message. Please do not reply. ***")
 
     # compose mime message