An interesting rcode is `NXDOMAIN` (3, or ``pdns.NXDOMAIN``), which specifies the non-existence of a domain.
Instead of setting an rcode and records, it can also set fields in the applied policy to influence further processing.
-The :func:`ipfilter` and :func:`preoutquery` hooks are different, in that :func:`ipfilter` can only return a true of false value, and that :func:`preoutquery` can also set rcode -3 to signify that the whole query should be terminated.
+The :func:`ipfilter` and :func:`preoutquery` hooks are different, in that :func:`ipfilter` can only return a true or false value, and that :func:`preoutquery` can also set rcode -3 to signify that the whole query should be terminated.
The :func:`policyEventFilter` has a different meaning as well, where returning true means that the policy hit should be ignored and normal processing should be resumed.