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Re: Well formed verses Valid code


From: Alastair Campbell
Date: Feb 26, 2007 9:40AM

Andrew Kirkpatrick wrote:
> Alastair, How do you differentiate between invalid html
> interfering with accessibility and interfering with proper

Hi Andrew,

This came up in the context of a accessibility audit against WCAG 1, so
checkpoints for JavaScript and valid HTML applied.

> The example you show is interpreted in different browsers
> but not just when assistive technology is in operation. This issue
> potentially all users with JavaScript off, not just disabled users.

Quite right, it is definitely one that I would consider potentially an
issue to many, regardless of ability. This one is about correct use of
the HTML standard so that any UA (should) be able to render it properly.

In practice, I would consider it something that should be caught in
general QA, rather than something that will affect people with
disabilities in particular.

> I'll agree that the invalid code shown makes consistent rendering less
> likely in this instance, but I'm not sure that I'd call it an
> accessibility issue - just an issue.

I suppose you could argue that people with disabilities are more likely
to be using an alternative user-agent, but I wouldn't try very hard on
that one!

This might be of interest:

> I'm in favor of accessibility standards that address issues that
> affect users, but not for a standard requiring valid code.

I know what you mean, but I've been quite glad of the accessibility
carrot/stick including valid HTML. It has improved the quality and
interoperability of several projects I've been involved with which would
have disregarded it otherwise.

If they are using CSS for layout, it's generally a necessary step to use
valid HTML, but otherwise it's very hard to eject the tag-soup habits.

Kind regards,


Alastair Campbell | Director of User Experience

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