Usability & Maintainability pf.conf Syntax Theo is trying to relax some of the rules of the syntax: Ordering of keywords braces "{ }" in lists of hosts: The macro expansion nightmare windows_hosts = "{" $host1 $host2 "}" broken_hosts = "{" $host3 $host4 "}" block in quick from any to $windows_hosts $broken_hosts 2.5 hackathons spent failing to fix this Hostnames are converted to IP addresses at the wrong point in the parser stack IPv6 makes this about 6 times as hard