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Path: utzoo!watmath!clyde!burl!hou3c!Margolin@MIT-MULTICS.ARPA
From: Margolin@MIT-MULTICS.ARPA (Barry Margolin)
Newsgroups: net.mail.headers
Subject: Re: Name data base or Name and Host data base
Message-ID: <840919064304.199768@MIT-MULTICS.ARPA>
Date: Wed, 19-Sep-84 02:43:00 EDT
Article-I.D.: hou3c.848
Posted: Wed Sep 19 02:43:00 1984
Date-Received: Thu, 4-Oct-84 03:22:18 EDT
Sender: ka@hou3c.UUCP (Kenneth Almquist)
Lines: 11
To: Jacob_Palme_QZ@QZCOM.MAILNET
Cc: header-people@MIT-MC.ARPA

A problem with your proposals (2) and (3) is that they violate the
sanctity of the local-part.  Your software that might try to recognize
          AAA!BBB!CCC%DDD@EEE
 as meaning the user CCC on Usenet host BBB would be making possibly
incorrect assumptions about how EEE parses its local parts.  On a
suitably unusual computer "AAA!BBB!CCC%DDD" could be a local user name;
there is no way for your site to know how what those special characters
mean to EEE.  If, perhaps, you know that EEE treats % in the local part
as synonymous with @, then you have the next level of assumption, about
how DDD parses ITS local-part, and then AAA.
                                        barmar