> 
> > Mark Andrews wrote:
> > 
> > > The Internet went to multi-label hostnames ~20 years ago.
> > 
> > As noted in RFC 2821 as "one dot required" syntax, also
> > mentioned in RFC 3696.  Recently *overruled* by 2821bis.
> 
>       There is a difference between allowing protocol to be used
>       in a "local" only mode (single label) and a "global" mode
>       (multi-label) and saying you must support single label in
>       a global context.
> 
>       Single label names are local in scope.  Attempting to use
>       them in a global context does not work.  As the names in
>       "." get more interesting the probability of collisions with
>       existing names goes up.  Not many people choose two letter
>       labels for the least significant parts of their host names
>       unless they are choosing their initials.
> 
>       Museum on the other hand is a real English word.  I'm sure
>       you will find lots other uses of "museum" in the DNS.  The
>       same thing will happen with other TLD's as the rules are
>       relaxed.
> 
>       Single label hostnames are not globally unique.  They SHOULD
>       NOT be used in a context where globally unique names are
>       required.
> 
>       Mark

        Additionally we have RFC 1535 warning about the consequences
        of treating global address as local in a addition to choosing
        a bad definition of local for a search list.

        The reverse is equally true.  Mail that was intended for a
        local receipient may end up being delivered globally.  Not
        everyone in a organisation tracks the comings and goings
        of local addresses.

        The sender may not even be local if a .forward contains
        "[EMAIL PROTECTED]" and tld goes away locally.

        Mark
-- 
Mark Andrews, ISC
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742                 INTERNET: [EMAIL PROTECTED]
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