To: kai@khms.westfalen.de (Kai Henningsen)
Cc: drums@cs.utk.edu
Subject: Re: smtpupd-02 
In-Reply-To: Your message of "01 Aug 1996 09:24:00 +0200."
             <6E1r4CEzcsB@khms.westfalen.de> 
Date: Sun, 04 Aug 1996 02:50:09 +1000
Message-Id: <7776.839091009@munnari.OZ.AU>
From: Robert Elz <kre@munnari.oz.au>

    Date:        01 Aug 1996 09:24:00 +0200
    From:        kai@khms.westfalen.de (Kai Henningsen)
    Message-ID:  <6E1r4CEzcsB@khms.westfalen.de>

    I still think we should
    1. Give a syntax definition that is as lenient as possible
    2. Say that the allowed names are further restricted by other RFCs, and,  
    if possible, name these
    3. Say, in a footnote or similar, what the current such restrictions are  
    and that they can change

This is all perfectly fine, as long as we don't assume that the
DNS imposes any restrictions (other than on lengths).

Right now, the best I can find for naming restrictions (or if
you like, the most restrictive) is 952 (as modified by 1123).
I'm not sure that I would really want to refer to that, it is
a bit long in the tooth (it is defining the DoD host table format).

Note that 822 does impose domain name restrictions - domain names
are (ignoring domain literals) composed of atoms, and atoms
can't contain white space, or special characters (eg: you can't
have a ':' in an 822 domain name - nor can you have a '.' that
isn't a domain label separator).   The DNS has neither of those
restrictions.

If 822bis is to defer to someplace else for domain name rules,
I think we're going to need to find the somewhere to do that,
or create it.   I don't think it is reasonable to say that
"some other RFC which may never be written will give the rules".

kre