Re: Gnus: UTF-8 and compatibility with other MUAs

[Simon Josefsson <jas@extundo.com>]

Xavier Maillard <zedek@gnu-rox.org> writes:

> Hi,
>
> I know Emacs is able to use utf-8 encoding so Gnus is.
>
> My question is more a question of compliance with other MUAs.
> Would you recommend your users to use utf-8 as a default encoding
> system ? AFAIK, I can't see many MUAs aware of it and worst almost
> nobody is using utf-8 which was presented as the future. So what is the
> problem with utf in general that prevent users in general to use it
> defaultly ?

IMHO:

Users should use the oldest charset widely deployed, or preferred, in
their own geographic region that is able to encode what they write.

This means if a user write only ASCII, it is tagged as ASCII (or
rather not tagged at all).

And if a (northern?) European user write å it should use iso-8859-1.

And if a european user write Ελληνικά it should use iso-8859-7.

And if a european user write € it should use iso-8859-15.  (One could
argue that iso-8859-15 is too recent and that it may make sense to go
directly to UTF-8, but my experience, as a northern european user, is
that iso-8859-15 is more appropriate, since the almost-compatibility
with iso-8859-1 is friendlier for people with old software.)

And if a european user write € and ά it should use UTF-8.  (I'm
assuming no 8859-* can encode both € and ά.)

This also means that it is wrong to use JP-2022-2, for european users,
even though it technically may be able to encode some strings, that
contain characters from 8859-* that isn't available in any single
8859-*.  Instead they should go to UTF-8.

I think this is how Gnus works though, unless you are in a UTF-8
locale and uses an old Emacs (then I think it will skip the 8859-*
step, but I might be wrong).

This logic might be flawed if the receiver is in another geographic
region, of if a user mostly communicate internationally.  Still, I'd
probably use the above logic even if I sent something to a Japanese
user, and expect them to use JP-2022-2 (or whatever) in return.

Perhaps some day we can try ASCII first, then fall back to UTF-8.  But
that will take a long time.  Even moving to ISO-8859-1 in northern
Europe took a long time, and still isn't finished.  I still use IBMPC2
(CP437?) in some regional communication channels.