W3C home > Mailing lists > Public > public-html@w3.org > February 2009

Re: "downplayed errors"

From: Jon Barnett <jonbarnett@gmail.com>
Date: Tue, 10 Feb 2009 14:52:14 -0600
Message-ID: <bde87dd20902101252o7e1671acxc631971cff082724@mail.gmail.com>
To: HTML WG <public-html@w3.org>
On Tue, Feb 10, 2009 at 11:37 AM, Robert J Burns <rob@robburns.com> wrote:

> On Feb 9, 2009, at 8:32 PM, Ian Hickson wrote:
>> As far as I can tell we already have consensus on alt="" being required.
>> (With one or two exceptions, the spec requires alt="" to be present. The
>> exceptions are machine-checkable.)
> I can't imagine at all how you think these could be machine-checkable
> criteria when it comes to omitting alt. Could you tell us a little about
> what you're thinking?

There are three bullet points in that are machine-checkable when
@alt is omitted.  The <figure> and <article><h1> cases are pretty
semantically specific.  The @title case is a little less specific. (There
may be more cases where @title may be present but don't match the semantics
for when @alt is omitted - key part of content with no suitable alternate)

Does that make sense?

To me the easiest way to make this machine checkable is to remove those few
> conditions that allow the alt attribute to be omitted and always require the
> attribute (of course allowing authoring tools to produce non-conforming
> documents when authors fail to provide conforming alt text as any other case
> when an author uses an authoring tool to produce a non-conforming document).

And then in doing so you make the semantics of those more ambiguous and less
machine-checkable (irrelevant vs. relevant images) - unless we go back to
the discussion of adding extra markup for those cases (another thread, I'm

As it stands, machines can give better error and warning messages for <img>
elements covering more varied use cases.

Jon Barnett
Received on Tuesday, 10 February 2009 20:52:54 UTC

This archive was generated by hypermail 2.3.1 : Thursday, 29 October 2015 10:15:42 UTC