On Wed, Jul 15, 2015 at 03:13:35PM -0400,
John C Klensin <john-ietf(_at_)jck(_dot_)com> wrote
a message of 74 lines which said:
a separate DNS CLASS, say "SN" for "Special Name". Zero impact on
the ICANN/IANA root from queries gone bad, no conflict with names
ICANN allocates even if the labels are the same (remember that
QCLASS=ANY has never worked), etc.
Classes in DNS are an old idea (see
<http://web.archive.org/web/20091227142955/http://net4d.org/index1.html>
for a defunct project) see the recent thread starting on
<http://mailarchive.ietf.org/arch/msg/dnsop/2JzQL2TeNc63qOoD7zl84Yu8p1I>
on dnsop, to see why it's a bad idea.