add a commented out scrub example

ok frantzen@

src/etc/pf.conf

@@ -1,10 +1,14 @@
-#	$OpenBSD: pf.conf,v 1.4 2002/06/17 08:07:58 henning Exp $
+#	$OpenBSD: pf.conf,v 1.5 2002/06/22 10:19:13 henning Exp $
 #
 # See pf.conf(5) for syntax and examples
 #
 # replace ext0 with external interface name, 10.0.0.0/8 with internal network
 # and 192.168.1.1 with external address
-#
+
+# Normalize:  reassemble fragments and resolve or reduce traffic ambiguities
+
+# scrub in all
+
 # nat: packets going out through ext0 with source address 10.0.0.0/8 will get
 # translated as coming from 192.168.1.1. a state is created for such packets,
 # and incoming packets will be redirected to the internal address.
@@ -29,4 +33,3 @@
 # block in log all
 # pass  in  on ext0 proto tcp from any to ext0 port 22 keep state
 # pass  out on ext0 proto { tcp, udp } all keep state
-