Re: empty quoted strings and other oddities

Bruce Lilly <> Wed, 02 October 2002 10:37 UTC

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Date: Wed, 02 Oct 2002 06:37:20 -0400
From: Bruce Lilly <>
Organization: Bruce Lilly
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Subject: Re: empty quoted strings and other oddities
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Keith Moore wrote:
>>RFC 2822 permits (as did 822) a quoted string which
>>consists solely of a pair of DQUOTE characters.  It's
>>not clear what the semantics of that are or ought to be.
> it doesn't have to have semantics, since quoted-strings
> can be used in places where they are opaque.  if someone wants their 
> email address to be "" this is perfectly legal.

OK, I'll buy that (at least 2821 and 2822 are consistent
in permitting it).

>>Likewise, a domain literal can consist solely of the
>>square brackets.
> so? there are lots of addresses which are valid syntax but 
> not valid because the domain is not defined or the IP
> address (in the domain literal) does not exist or is not
> assigned to a host.

I'm not sure that there aren't MTAs or MUAs that would
break or pass bizarre requests to DNS when trying to
deal with [] as a domain literal.

Also, in this case 2822 seems to be alone in permitting
that syntax, which is not permitted by 2821 or 1123.