On Wed, Jul 15, 2015 at 03:13:35PM -0400, John C Klensin <john-ietf@xxxxxxx> 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.