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Thread: Is doctype really important
Number of posts in this thread: 7 (In chronological order)
From: Chris Price
Date: Sun, Mar 14 2004 6:10PM
Subject: Is doctype really important
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In the WAG guidelines we are told that a page should "validate to published
formal grammars" and recommends including a doctype.
I have found that a doctype definitely makes a difference when relying on
style sheets for layout but many commercial sites don't include a doctype
and I can only presume they don't see the need for one.
How important is a doctype in terms of accessibility and can the lack of one
make any real difference when it comes to a table based layout.
--
Chris Price
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From: Paul Bohman
Date: Sun, Mar 14 2004 6:43PM
Subject: Re: Is doctype really important
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When it comes right down to it, if the page is coded with all of the
appropriate accessibility features, the doctype is not important. A
missing doctype is not going to break the accessibility of the page if
everything else is done well.
However, a missing doctype is usually symptomatic of additional
problems, and indicates a bit of laziness on the part of the developer.
Chances are that if you're not coding in valid HTML, you're also
forgetting other things, whether you realize it or not.
And, as you mentioned, browsers are better able to serve out the content
when the doctype is present.
Chris Price wrote:
> How important is a doctype in terms of accessibility and can the lack of one
> make any real difference when it comes to a table based layout.
--
Paul Ryan Bohman
Web Accessibility Specialist/Project Coordinator
WebAIM (Web Accessibility in Mind)
www.webaim.org
Center for Persons with Disabilities
www.cpd.usu.edu
Utah State University
www.usu.edu
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From: julian.rickards
Date: Mon, Mar 15 2004 7:35AM
Subject: RE: Is doctype really important
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>
From: Larry G. Hull
Date: Mon, Mar 15 2004 8:28AM
Subject: RE: Is doctype really important
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As far as I'm aware, doctype isn't specifically part of Section 508
but the absence of doctype certainly can be an accessibility issue
inasmuch as (1) you can't use a tool to validate your code without a
specification (DTD) against which to validate and (2) poor and/or
browser specific (acceptable) code can give assistive technology
problems.
From the W3C HTML 4.01 Specification at
http://www.w3.org/TR/REC-html40/struct/global.html#version-info
"A valid HTML document declares what version of HTML is used in the
document. The document type declaration names the document type
definition (DTD) in use for the document (see [ISO8879])."
In my opinion, browsers are sometimes a little too forgiving when
they accept (or ignore) bad or absent coding.
Larry
At 9:25 AM -0500 3/15/04, = EMAIL ADDRESS REMOVED = wrote:
> >
From: julian.rickards
Date: Mon, Mar 15 2004 8:47AM
Subject: RE: Is doctype really important
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Something else I have thought of.
I find that since adopting accessibility into my web design work, I have
been more concientious of valid and standard HTML, good (better) coding
practices and careful use of JavaScript. I attribute this change to my
interest in accessibility. I think that anyone who wants to or needs to
adopt accessibility into their web work will make the same types of changes
to their methods.
---------------------------------------------------------
Julian Rickards
Digital Publications Distribution Coordinator
Publications Services Section
Ontario Ministry of Northern Development and Mines
Phone: (705) 670-5608
Fax: (705) 670-5690
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From: Terence de Giere
Date: Mon, Mar 15 2004 1:56PM
Subject: Re: Is doctype really important
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Quite often now we see Doctype Declarations in web pages, much more so
than formerly. This first line in the page (it should be the first line
with nothing above it) is an instruction for an SGML or XML processing
system to tell it exactly what rules the structure of the code in the
page that follows is going to be. Most browsers until recently have
ignored the Doctype, but the newer browsers are now paying attention to
them. Especially if you use the 'strict' forms of HTML 4.0 or 4.01 or
xhtml 1.0 or you are using xhtml 1.1.
Most HTML on the Internet is invalid and out of specification. When
there is no Doctype, the HTML is undefined, and invalid, meaning that it
does not conform to specifically defined rules. When there is a Doctype,
the page might be valid HTML if it corresponds to the definition of HTML
specified by the Doctype. But it also might be invalid meaning that the
HTML in the page does not correspond to the Doctype. This latter
situation is very common on the web, the Doctype is there in the page,
but the HTML is the same old garbage HTML that appears in pages without
the Doctype. The purpose of the Doctype is to restrict the HTML in your
page to specific set of rules so the HTML has a known defined structure.
Then any HTML capable device that can process that Doctype can load the
page without error. It is especially important for CSS format because
the parse tree, the document structure has to have a precise definition
for the format to cascade down through all the page elements without
error, and for scripting to manipulate those same elements.
All the major browsers now have lots of error correction code to process
pages. So if the HTML is bad, it might get fixed, but you won't know by
looking at the page in the browser that there was a problem. But why
take a chance? Using a Doctype and validating your pages against that
Doctype is great quality control. A page without errors is less likely
to cause problems with all browsers because all browsers at least to
some extent rely on the various standards set by standards bodies and
industry consortiums. It is the safest path. HTML validation is similar
to compiling in other computer languages in that it checks for outright
syntax errors and other structural problems. Note: most HTML editors do
not validate HTML so having a Doctype is no assurance the HTML below it
is right. Dreamweaver by default adds a Doctype, but it will also allow
you to add things to the page that violate the Doctype. Dreamweaver also
has an HTML checker that incorrectly validates pages. You need to use an
external validator with most editors that follows the specifications for
SGML and/or XML.
Valid HTML pages are also forward compatible, as time goes on, more
browsers and other technologies incorporate the current standards, and
as smaller web access devices with less HTML error correction are
appearing all the time now, it is advisable to have the cleanest, most
standardized code possible.
Terence de Giere
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From: Andrew.Arch
Date: Mon, Mar 15 2004 10:36PM
Subject: Re: Is doctype really important
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I understood that 'doctype' actually gives you more insurance about how
your page will display now that IE looks for it.
E.g. "if you use the following Doctype on new pages ...<!DOCTYPE HTML
PUBLIC "-//W3C//DTD HTML 4.0 Strict file://EN">... users with IE 6 will
have their browsers automatically switched into standards-compliant mode
and your pages will be rendered according to the standard -- which,
happily, is how Netscape 6 renders the code as well" [Jeffery Veen, IE 6
Switches to Standards, 2001-
http://hotwired.lycos.com/webmonkey/01/14/index0a.html &
http://hotwired.lycos.com/webmonkey/01/14/index0a_page2.html?tw=authoring]
Andrew
Chris Price
<chris.price@choc To: < = EMAIL ADDRESS REMOVED = >
taw.co.uk> cc:
Subject: Is doctype really important
15/03/2004 12:03
PM
Please respond to
webaim-forum
In the WAG guidelines we are told that a page should "validate to published
formal grammars" and recommends including a doctype.
I have found that a doctype definitely makes a difference when relying on
style sheets for layout but many commercial sites don't include a doctype
and I can only presume they don't see the need for one.
How important is a doctype in terms of accessibility and can the lack of
one
make any real difference when it comes to a table based layout.
--
Chris Price
----
To subscribe, unsubscribe, suspend, or view list archives,
visit http://www.webaim.org/discussion/
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