The W3C Validator is a black and white, pass or
fail situation with no middle ground. It will fail
pages that work perfectly well in all current
browsers - including some of mine. This is because
current browsers still have some, (if not as much as
before) latitude or forgivingness built-in. You
can't count on this always being so. If you want
your pages to keep on working, make them W3C
compliant now.
There are some potential problems that the W3C
Validator won't show up. A page that is perfectly
valid in terms of coding might still look wrong. The
important principle of separating structure and
content is like building two houses from the same
set of plans - without dimensions. The houses could
have completely different sizes, finishes and
colours. One could be okay for humans and the other
only for dolls.
The HTML is the 'skeleton' of a Web page and the 'look'
is determined by the Style Sheet. Well, that is the
principle and where things are headed but in the
real world, the legacy of older browsers and Web
pages still in use means that you can never be sure
of anything working correctly anywhere.
In the end, it's your decision. You can address the
lowest common denominator and design a page that
works at a basic level for everybody or you can use
the latest technologies that only work in the newest
browsers - or anything in-between.
Ignore the problem and it will go away.
Unfortunately, using a validator like the one at W3C
can be a little confusing and even frustrating. Why
is it giving errors when the page works just fine in
every browser you've tried it in? Is it really
possible to get an error-free page and if you did,
would it work in any browser?
Well, just like WYSIWYG editors, there are no
bug-free browsers. If a browser is interpreting a
page of HTML and comes across something it doesn't
understand, it should ignore it completely. If
Microsoft Internet Explorer sees a <chuckle> tag in
HTML 4.01, it just pretends it hasn't seen it and
nobody really cares.
The W3C Validator, and any other one of any value,
will complain bitterly that there is no <chuckle>
tag in this version of HTML. That's what it is
supposed to do.
The browser has dealt with the problem by ignoring
it but the validator isn't too happy about you
taking the mickey.
Not all such problems are so clear-cut. There is a
point at which any browser gets utterly confused and
can't make any sense of what it is given. What it
does in that case is anyone's guess.
Some common validation errors and what they really
mean:
Error: there is no attribute "LEFTMARGIN" for this
element (in this HTML version)
Error: there is no attribute "TOPMARGIN" for this
element (in this HTML version)
Error: there is no attribute "MARGINHEIGHT" for this
element (in this HTML version)
Error: there is no attribute "MARGINWIDTH" for this
element (in this HTML version)
What's the worst that can happen?
The browser will ignore these attributes and your
graphics won't butt-up against the edge of the page.
Error: there is no attribute "HEIGHT" for this
element (in this HTML version)
What's the worst that can happen?
The browser will ignore the "HEIGHT" you set for a
table and it will collapse vertically until it
encounters some content that stops it from shrinking
any further.
Error: required attribute "ALT" not specified
What's the worst that can happen?
The "ALT" attribute for an image is used by screen
reading software for visually impaired people and
should tell them what they can't see. Sometimes it
doesn't make sense to describe an image – like a
clear spacer GIF, for instance. The correct thing to
do is to provide an ALT = "" – an empty string.
Error: there is no attribute "NAME" for this element
(in this HTML version)
What's the worst that can happen?
If you were to address an image in a rollover by its
NAME attribute (as is quite common) and the browser
ignored it, the rollover wouldn't work and would
probably throw a JavaScript error too. However, the
"NAME" attribute is undertood by most browsers and
valid since HTML 4.01. You will get this error if
you specify HTML 4.0 or earlier in the DOCTYPE.
It's getting increasingly difficult to make pages
that work in all browsers without resorting to page
redirection hacks. At some time you are going to
have to decide, (hopefully based on some hard
evidence from your server stats), that you are no
longer going to support older browsers. Some people
are doing that already but exactly where to draw the
line is not an easy decision.
No matter how hard you try, sometimes your code will
just not pass the W3C Validator test. You might, for
instance, have a link to an external banner ad that
is serving up non-compliant code. You have to be
sensible about such things, absolute perfection is
an ideal that doesn't justify insanity.
Meanwhile back on the building site, it's raining
hard and all the mortar is being washed out from
between the bricks.
The wind has blown away the tarpaulin that was
acting as a makeshift roof and the local building
inspector has just pulled up in his car.
