Private DNS Domains

[John Devitofranceschi]

A colleague of mine and I were talking about our internal/external
(split) DNS setup.  We came around to discussing the possibility 
of 'formally recognized' (by RFC) private domains, like the private
networks defined by RFC 1918. 

Has this idea been discussed?  It seems like a neat way to avoid
needing to implement an internal 'fake root' zone.  You could simply
have DOMAIN.com be your external name and DOMAIN.pvt (pvt
or prv, for private) internally. Some minimal extra smarts in bind to 
deal securely with private domains and off you go!

Thoughts?

jd