Re: texi2html output validity

[Ineiev]

On Fri, Dec 26, 2014 at 12:58:24AM +0900, Stephen J. Turnbull wrote:
> Ineiev writes:
>  > On Wed, Dec 24, 2014 at 12:27:25PM +0900, Stephen J. Turnbull wrote:
>  > > AFAIK the encoding declaration is optional, defaulting to UTF-8.  In
>  > > that case, we can (and IMHO *should*, but I am no longer an expert on
>  > > current encoding practice) require that our software generate UTF-8
>  > > and omit the declaration.  Non-UTF-8 should be invalid in Info-HTML.
>  > 
>  > The fact is that some users have ASCII-incompatible default
>  > encodings (like UTF-16). if we add the declaration, it costs little,
>  > but the pages just work for them.
> 
> AFAIK, default encodings are not a problem.

GNU webmasters did receive reports from such visitors. I'm sure many
cases were not reported.

> If Info-HTML is specified
> to be served as XML (which has its own issues, but that's one way to
> do it) then conformant browsers RFC2119-MUST assume Unicode as the
> coded character set, and will automatically determine the
> transformation format (UTF-8, UTF-16, UTF-16-little-endian) by
> checking the first two octets.  I believe HTML5 also specifies UTF-8
> as the default.

I don't think HTML5 requirements are relevant because the browser
may not realize that it's HTML5 rather than HTML4 (and if we use <tt>,
we have few options but to produce HTML4, anyway), and for HTML4,
it obeys user's bogus settings.

Of course there may be ways to specify the encoding other than the
explicit declaration; I just believe that the explicit declaration
works reliably, and I'm not sure about other means.

> Alternatively, for such systems it's trivial to generate UTF-16 from
> UTF-8.

I think I don't understand this. do you suggest that webmasters
provide two versions of pages for the users to select them manually,
or do you say that the users should convert the pages themselves?