Excerpts from internet.ietf-822: 24-Apr-91 Re: Comments on Draft RFC
Vincent Lau(_at_)eng(_dot_)sun(_dot_)com (1611)
I would like to see a stronger statement that implementations *should*
discard the "prefix" and "postfix" areas. Don't recommend the use of them.
I am afraid that if a sending UA puts an important (judgment call) message
in the prefix area, but the receiving UA discards it. In my opinion, these
2 UA's are *not* interoperable.
I'm happy to say they should be discarded. But are you also arguing
against the short textual message saying, in effect, "this is a
multipart message; if you're seeing this, you've got a problem"? That
still seems like a good idea to me.
Excerpts from internet.ietf-822: 24-Apr-91 Re: Comments on Draft RFC
Vincent Lau(_at_)eng(_dot_)sun(_dot_)com (1611)
Content-Label is set by the *sending* UA (e.g. the sender assigns a label
"Phone_Message" to an audio typed body part) and it is more user-friendlier
than Message-ID when used in a reply message. This field exists in each
body part, but it is optional. Message-ID is different from Content-Label
that Message-ID refers to the whole message and Content-Label refers to a
specific body part in a message.
Ah, but in a multipart message, each "body part" is an encapsulated
message, and can therefore have its own message-id header. Therefore
they are, I believe, functionally identical. I'm also not sold by the
argument to "user-friendliness" because I think that, in either case,
the header field is intended for software use rather than for human
reading. Or is this assumption incorrect?