Hence, there is the sender's view, the 'byte' (or thereabouts) view of
the interpretable data, and finally the transmission convention.
So, I might have
1. nroff
2. USASCII
3. Quoted Text
One thing that should be considered, is the functionality of these
headers. With the content-type/content-encoding pair the matter is quite
simple: first the UA unpacks the body by feeding it through all the
decoders mentioned in the content-encoding header. Then it chooses the
right viewer for this part according to the content-type header.
How does a content-charset or something like that fit into this? Is the
charset passed as a parameter to the viewer? Maybe it would then be
better to place the charset indicator as a parameter to the content
type. Or maybe there is a different viewer for each pair, that pair
could be used as the content-type name, like X-nroff-USASCII. There is
probably some lookup table for the different contents and their viewers.
Even if there is a single viewer for the different character sets, that
could be handled with this table, if this latter style is used:
X-nroff /usr/bin/nroff -c ascii
X-nroff-USASCII /usr/bin/nroff -c ascii
X-nroff-Latin1 /usr/bin/nroff -c ISO-8859-1
Also, a separate character set header would be needed only for these
kind of special cases. Most text formats handle the charset issue
themselves (like WP documents) and graphics or voice parts don't have
this at all. So, I'd prefer a more general method instead of a specific
header. I think we could manage with using X-nroff-USASCII style content
names, or we could use the resource-ref part for this (e.g. Content-
type: X-nroff;;me,Latin1). I don't know, if the RFC822bis should decide
this in general.
Btw. RFC1049 allows one to leave out the ver-num part, if there are no
resource-refs, but requires it when they are present. Is there a reason
for this?
--
Risto Kankkunen kankkune(_at_)cs(_dot_)Helsinki(_dot_)FI
(Internet)
Department of Computer Science kankkunen(_at_)finuh (Bitnet)
University of Helsinki, Finland ..!mcsun!uhecs!kankkune (UUCP)