-1. Add no-equal-brothers restriction for subdomains (RFC1034).
+1. Use a typeclass for all the length operations on Domain types.
+
+2. Write a library for Nagios plugins (or "Monitoring plugins" as the
+ Perl library now calls them).
+
+3. Add a CLI nagios-check-harbl (or whatever) executable that utilizes
+ the harbl library and reports erros in a Nagios-friendly format.