utf-8 -> latin-X if possible

[Simon Josefsson <jas@extundo.com>]

Sorry if this has been beaten to death, but I still don't understand
it, so:

I've started to use

  (prefer-coding-system 'utf-8)

since that gives me better utf-8 support in emacs, but it seems Gnus
start to send messages in utf-8 then.

How do I get Gnus to send it using latin-X, if possible, instead?

I tried loading ucs-tables.el, and invoked unify-8859* and ucs-unify*
in the message buffer, but it did nothing.

Wouldn't it be nice if there were a section explaining this stuff in
the manual?  I'll write it when I get this to work the way I want.

(I used to call `(prefer-coding-system 'latin-1)' after the statement
above to get latin-1 preferred over utf-8 again, but I'd like to not
do that.  It seems as if I'd like to prefer utf-8 on reading but
latin-1 on writing, not sure if that's possible.)