On 01/11/2018 04:39 PM, Dave Royal wrote:
> Theoretically, yes; but I've never seen such a message. Though provided
> one alternative is text/plain I probably wouldn't have noticed.
I guess part of what I find odd is that most messages have a
Content-Type containing text/plain. Even Bob's message sharing the
following rule had a Content-Type containing text/plain.
If "Content-Type" "contains" "text/plain" then "delete"
> It's hard to be sure whether any particular RFC is the latest,
I don't think that's entirely accurate.
1) You can find if an RFC has been updated via the RFC index at the RFC
Editor's website.
2) You can go to the IETF and see the data tracker for the RFC / BCP
and it will tell you if there are updates.
It takes a little bit (~45 seconds) of work but it is possible.
> but AFAICS multipart mime messages are defined in RFC1521.
https://tools.ietf.org/html/rfc1521 page header
[Docs] [txt|pdf] [draft-ietf-822ext...] [Diff1] [Diff2]
Obsoleted by: 2045, 2046, 2047, 2048, 2049 DRAFT STANDARD
Updated by: 1590
Network Working Group N. Borenstein
Request for Comments: 1521 Bellcore
Obsoletes: 1341 N. Freed
Category: Standards Track Innosoft
September 1993
So we can tell that RFC 1521's most up to date version is 2049.
;-)
> NNTP messages
> are defined in RFC5536 of which section 2.3 specifies MIME conformance;
> this includes internationalisation but does not mandate RFC1521. At the
> end of that section it says that other MIME extensions are optional.
Extensions to the MIME (or almost any) specification add to and very
seldom override / remove. (At least not without good, documented, reason.)
I've not recently read any of those RFCs, so I can't speak authoritatively.
That being said, I think that the content type is assumed to be
text/plain if MIME is used and there is no other content-type declaration.
> So an NNTP-compliant newsreader may not be able to read html, or display
> just the text from a multipart message. But in that case I think it must
> display all parts and treat them all as ASCII.
I find that to be highly questionable. But I can see how someone can
arrive at that logic.