On Thu, 19 May 1994, Lennart Lovstrand wrote:
1. RTF is a text format directly comparable with Enriched and ought to be
registered the same way. Having it confined to the application type is
essentially saying that it should be used only for attachments.
The usual way that text is interpreted is "if you don't know the subtype,
it is probably still safe to blatt it straight to the screen and the user
will be able to make something out of it". Except for very carefully
constructed RTF documents (usually hand-crafted), I've yet to see one that
the user can make sense out of by looking at it directly.
RTF really was intended to be a standard way to swap files between
wordprocessors, not something a user would want to be concerned directly
with. There's no law that says that formats that may have cannonical
text representations must be tagged under "text". "text" does serve a
useful role to provide hints to the receiving software as to what should
be done by default with something unknown.
2. Text/Enriched is nice, but much too limited. If you're willing to take
the effort of implementing it, you might as well go all the way and adopt a
mature standard that is more capable. Enriched goes to great lengths to
avoid any metrics -- such as explicit font sizes, line heights, tab stops,
etc -- but I believe this to do more bad than good. Wouldn't it be better to
make the data as rich as possible and let the interpreter do as good job with
it as it can than to limit the data transmitted and thus lower the quality
with it?
Nope. If you want really high quality text output, it won't matter how
smart you make text/enriched. Things like RTF, Postscript, SGML, LaTeX, etc
are much better suited. If however you are after a few trendy things like
boldness and italics to beef up the output a little, then text/enriched
or Bill's text/simpletext (simplemail?) is fine.
It's a question of differentiating between writing an e-mail message and
writing a full blown text document. In the former you want something simple
so you can whip off the message quickly, but in the latter you want the full
facilities of a decent document formatting system. We in the MIME working
group are simply not qualified to produce a document formatting system, let
alone try to force everyone else to use it. We leave that to ISO. :-)
That is to say, wouldn't it be better to be able to say things like "9 point,
Helvetica, indented 1 inch, in color <252, 95, 95>" than "small, indented,
red". With the former, I have some chance of communicating the actual
appearance of the text; with the latter, it's pretty much just guesswork --
and I'll never be able to do things like specific alignments for bulleted
lists. If you define a standard metric, you can induce things like "9 point"
=> "smaller", but you can't go the other way around without losing
information.
Appearance information is actually not a good thing to have in a format such
as text/enriched. "Helvetica, indented 1 inch, in color <252, 95, 95>"
means absolutely nothing to a text/enriched interpreter outputting to a
dumb terminal, so what is one supposed to do with it? Ignore it? Remove
all the text in the trendy font? Take a wild guess?
The avoidance of metrics was a conscious design decision. Take a number of
features that are likely to be available in most environments, or can be
ignored in those that don't have them, and then let the local software
display those features in the best way possible, with only a minimum of
style guidelines. This was intended to aid interoperability.
Or is it rather that the majority of MIME folk aren't very interested in
exchanging "higher resolution" text or see it as practically unobtainable?
You _can_ exchange higher resolution text, in many other formats which are
much better suited to it than poor old text/enriched.
I've been a long-time champion of text/enriched, but I now think that
maybe we should depreciate it in favour of HTML, since that seems to be
more popular these days, and is more flexible. Except for a few example
MIME messages, and stuff from Nathaniel, I don't think I've every received
any text/enriched (or the earlier text/richtext) messages, let alone
text/simpletext messages. (I haven't received any HTML messages either,
but you know what I mean :-) ). What do others think? Too hard? Worth
pursuing? Couldn't care less?
Cheers,
Rhys.