+PP/04 First step towards DNSSEC, provide $sender_host_dnssec for
+ $sender_host_name and config options to manage this, and basic check
+ routines.
+
+PP/05 DSCP support for outbound connections and control modifier for inbound.
+
+PP/06 Cyrus SASL: set local and remote IP;port properties for driver.
+ (Only plugin which currently uses this is kerberos4, which nobody should
+ be using, but we should make it available and other future plugins might
+ conceivably use it, even though it would break NAT; stuff *should* be
+ using channel bindings instead).
+