[html5] HTML5 validator behavior issue

[Jukka K. Korpela]

Ian Hickson wrote:

> It's invalid, and it would be ideal if the validator said it was
> invalid, but for various reasons it's essentially impossible for the
> validator to detect this particular mistake.

That's rather obvious when "mistake" is defined as a violation of a loose 
prose requirement.

> Validators are not perfect, sadly. Really a validator should say "no
> errors found", rather than "valid document", it's not quite the same.

It's not at all the same of course.

In the goold old days, "validator" used to mean software that checked an 
SGML (or XML) document against reportable markup errors, basically checking 
its content according to the announced Document Type Definition.

In our days, "validator" more and more often means software that checks data 
against some opinions to the extent that these opinions have been coded into 
the software. A loose expression like "using the style attribute to hide and 
show content - - is non-conforming" is virtually impossible to enforce in 
automated software. For one thing, just saying display: none simply hides 
the content (under the usual CSS caveats), so it would be incorrect to say 
that it is used "to hide and show content".

-- 
Yucca, http://www.cs.tut.fi/~jkorpela/