| Configuration of identical SPF data in multiple zones should be
| entirely the responsibility of the zone file administrator who can
| use "include" directives, macros, scripts, and many other tools to
| ensure consistency of SPF data accross multiple domains.
I'm a big fan of M4 myself and I use Python or Perl to generate zone
files *but* it works only if the domain you "include" is in the same
administrative authority.
Let's assume my vanity domain, bortzmeyer.org, is entirely hosted by
my ISP Nerim and I want to "include: nerim.net". Should I dig
nerim.net and expand it? What when Nerim does change?