[whatwg] HTML5: compatible with all legacy Web browsers

Fri Aug 7 03:39:49 PDT 2009

On Thu, 06 Aug 2009 19:49:45 +0200, Elliotte Rusty Harold  
<elharo at ibiblio.org> wrote:

> Section 1.7:
>
> "The first such concrete syntax is "HTML5". This is the format
> recommended for most authors. It is compatible with all legacy Web
> browsers."
>
> I challenge the claim that HTML5 is compatible with *all* legacy Web
> browsers.

I guess it depends on the definition of "compatible".

> I can produce valid HTML 4 documents today that are not
> compatible with *all* legacy Web browsers.

That's irrelevant. Can you produce valid HTML5 documents today that are  
not compatible with all legacy Web browsers?

I guess the following is an example of a valid HTML5 document that is  
incompatible with legacy Web browsers:

    <!doctype html>
    <title></title>
    <svg><script/></svg>
    <p>Hello world</p>

> I suggest this be weakened
> to something like "is compatible with most Web browsers still in
> active use today".

What is it that is not compatible with which browser?

-- 
Simon Pieters
Opera Software