Re: Questions about RFCs 1494, 1495.

Ned Freed <> Sun, 05 June 1994 07:01 UTC

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Date: Sat, 04 Jun 1994 10:46:17 -0700 (PDT)
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From: Ned Freed <>
Subject: Re: Questions about RFCs 1494, 1495.
In-reply-to: Your message dated "Fri, 03 Jun 1994 10:03:09 +0200" <>
To: Justin Ziegler <>
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> 1)
> RFC 1494 defines:
> 	- mime-postscript-body,
> 	- mime-jpeg-body,
> 	- mime-gif-body,

> why not also define:

> 	- mime-partial-body,
> 	- mime-external-body,
> 	- mime-richtext-body,
> 	- mime-audio-body,
> 	- mime-mpeg-body.

> Later one would also have to define many others...

I would rather see these defined as FTBP objects. For one thing, it is much
less work to support these things using FTBP since the structure of the part is
broken out as a separate OID from the one that indicates what sort of
information is present in the part. This in turn means that adding new types is
simply a matter of adding simple entries to tables, rather than having to deal
with things at the ASN.1 level.

Unfortunately, FTBP terminology for the former OID is contents-type (note the
plural) while the latter  is application-reference. This doesn't match up well
with the corresponding MIME terminology at all. But this is strictly a
terminology issue, not a technical one.

> 2)
> Would it not be a good idea to put in the mime-postscript-body,
> and in the mime-jpeg-body, and in the mime-gif-body
>  a big parameter field
> like in the mime-body-part (except the content-type). This enables
> the mapping of content-description and all the other header fields.
> 	?

There's already a place for this in the FTBP.


P.S. Since FTBP is only specified in the 1992 draft of X.420, and additionally
references all sorts of other stuff from FTAM, X.227, and elsewhere, putting to
together a full definition is a real challenge. I've tried to take some of the
pain of doing so away by including one in the FTBP mapping specification I just

P.P.S. If anyone knows the definition of an Attribute-Extensions element I'd
love to know what it is so I can include it. I assume it is something in the
1992 revisions of FTAM, which I haven't gotten copies of yet.