Re: 10646, and all that

[Masataka Ohta <mohta@xxxxxxxxxxxxxxxxxxxxxxxx>]

> > Or, are you saying that the following specification:
> > 
> > 	Content-type: text/plain; charset=ASCII
> > 	Content-language: French
> > 
> > is better than:
> > 
> > 	Content-type: text/plain; charset=ISO646-FR
> >
> 
> Yes!  Actually I prefer a language= parameter, but I definitely want
> to separate the language specification from the character set.

That's contradicts with the current policy to use the name US-ASCII
to the only true ASCII.

> If the language is combined with a charset, then a decent mail reader has to
> support LOTS of charsets.  Especially when you start listing combinations of
> languages -- say, to indicate a mixed English/Japanese text.

If the language is encoded in a charset, and if the receiver want
to display the charset correctly, the receiver should provide support
for the charset.

If the language is encoded in a charset, and if the receiver does not
want to display the charset correctly, the receiver does not have to
provide support for the charset.

If the language is not encoded in a charset, if no language information
is provided otherwise, and if the receiver want to display the charset
correctly, the receiver can't.

> If language is a parameter to content-type, then a mail reader can display
> the message (perhaps sub-optimally) if it knows the character set.  If it's
> smart enough to take the language parameter into account, the mail reader
> can pick a font that is tuned to that language.

That is no different from the above examples.

> Furthermore, separating the language parameter from the charset makes it
> easier to do multilingual text using a construct similar to
> multipart/alternative -- the mail reader can let the user choose to read the
> French rather than the Spanish version of the text.

Then, you must provide very precise definitions of all the languages
in the world.

> The
> reader doesn't really care about the character set, as long as her mail
> reader supports it.

So, let's encode language information into charset.

						Masataka Ohta