Re: Syntax validation of articles by injecting agents

[Julien ÉLIE <julien@xxxxxxxxxxxxxxx>]

Hi Charles,

> > > But I don't think RFC 2049 ever intended to imply that MIME-Version was
> > > needed for a message that did not actually use any of the MIME features.
>
> > Hardly on topic for this list, but yes that's exactly what it means, and
> > what it was intended to mean.  It's no big deal for a client to generate
> > the header field, so it's hardly onerous!  (see this message for an
> > example of a compliant client)
>
> Then how do you account for the option of not including in in RFC 2047?

The Section 6.1 you quote in RFC 2047 only specifies how a MIME-compliant
reader MUST parse any messages.
The fact that a MIME-Version: header field is not required to be present
for <encoded-word>s to be interpreted according to the specification
only means, to my mind, that a MIME-compliant reader should properly decode
<encoded-word>s of broken agents.

This way, a MIME-compliant agent will not write
   =?iso-8859-1?q?this=20is=20some=20text?=
to the user if the MIME-Version: header field is missing!  It will try
to decode it and properly display "this is some text".

Another reason is given by RFC 2047:

      One reason for this is that the mail reader is
      not expected to parse the entire message header before displaying
      lines that may contain 'encoded-word's.

It then allows a MIME-compliant reader that decodes headers as soon as
it receives it, not to wait for the MIME-Version: header field in order
to properly decode headers.  It will not have to decode them twice
for instance.


Aren't these two reasons enough to say that RFC 2047 does not stipulate
that a MIME-Version: header field is optional?

If not, see Section 4 of RFC 2045:

  Therefore, this document defines a new header field, "MIME-Version",
  which is to be used to declare the version of the Internet message
  body format standard in use.

  Messages composed in accordance with this document MUST include such
  a header field, with the following verbatim text:

    MIME-Version: 1.0

  The presence of this header field is an assertion that the message
  has been composed in compliance with this document.


Regarding RFC 2045:

  This initial document specifies the various headers used to describe
  the structure of MIME messages.  The second document, RFC 2046,
  defines the general structure of the MIME media typing system and
  defines an initial set of media types.  The third document, RFC 2047,
  describes extensions to RFC 822 to allow non-US-ASCII text data in
  Internet mail header fields.  The fourth document, RFC 2048, specifies
  various IANA registration procedures for MIME-related facilities.  The
  fifth and final document, RFC 2049, describes MIME conformance
  criteria as well as providing some illustrative examples of MIME
  message formats, acknowledgements, and the bibliography.

--
Julien ÉLIE

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