Re: MIME Multiple body parts (Was Re: uid...)

[Doug Royer <Doug@xxxxxxxxx>]

"Shannon J. Clark" wrote:
> 
> Doug,
> 
> Just a thought along these lines:
> 
> 1 - are we discussing a MULTIPART composed of iCalendar related objects?
> (some encrypted, some not perhaps?)

YES

> or
> 
> 2 - are we discussing a MULTIPART composed of a text or text/html object +
> an iCalendar object?

AND
YES

> Also - if the iCalendar object has say an Attachment - are we considering
> allowing that ATTACHMENT to be bundled as part of the MULTIPART message,
> and/or for that ATTACHMENT to be encrypted in some manner?
> 
> Shannon

We allow attachments (AKA body parts) because we allow CID's and MID's
as URL's in the vCalendar object. That means that one MIME message as
MULTIPART/RELATED can have N-number of body parts, one of which
is the vCalendar object (text/calendar).

A CID is a CONTENT-ID, and means that one URL in the text/calendar
body part refers to the contents of another body part in the same MIME
message. Example:

	URL:cid:body-part-2

(note: I may not have correctly shown a CID or MID url, but
 you'll get the idea).

A MID is a MESSAGE-ID to a MIME body part. That means that
a text/calendar body part can refer to any body part in any other
MIME message. Example:

	URL:mid:royer.com/~doug/message-3/body-part-3

Also, the WG agreed that MULTIPART/ALTERNATE was expected to
be allowed. (one part text/calendar, others any other representation
of the object text/plain, text/html, ...). Example:

	MIME-header ... MULTIPART/ALTERNATE

	<body-body-part-one ... text/calendar>
		BEGIN:VCALENDAR
		...
		END:VCALENDAR
	<end-body-part-one>
	<body-body-part-two ... text/plain>

	You have been invited to a party 
	Starts at: ....
	Ends at: ...
	...

	<end-body-part-two>

This DOES NOT mean that a CUA or a CS MUST implement the code
to process these. It mean that we agreed not to limit ourselves
and allow CID/MID's.

NOTE: MULTIPART/<whatever> may be combined/mixed and contain
other MULTIPART/<whatever>

Again we are not mandating that a CUA or CS MUST do this, we
are simply not restricting them from using all of MIME.

-Doug