documentation update

--HG--
branch : trunk
diff --git a/jinja2/exceptions.py b/jinja2/exceptions.py
index e5b156b..2653952 100644
--- a/jinja2/exceptions.py
+++ b/jinja2/exceptions.py
@@ -18,6 +18,12 @@
     """Raised if a template tries to operate on :class:`Undefined`."""
 
 
+class SecurityError(TemplateError):
+    """Raised if a template tries to do something insecure if the
+    sandbox is enabled.
+    """
+
+
 class TemplateNotFound(IOError, LookupError, TemplateError):
     """Raised if a template does not exist."""