- From: Jon Ribbens <jon+www-validator@unequivocal.co.uk>
- Date: Tue, 23 Nov 2004 14:31:50 +0000
- To: www-validator@w3.org
Olivier Thereaux <ot@w3.org> wrote:
> > It would be very helpful if there was a page somewhere as part of the
> > validator, maybe on the FAQ page, describing the sort of things that
> > are incorrect HTML but will not be detected by the validator, perhaps
> > with a few examples.
>
> There's http://validator.w3.org/docs/help.html#validandquality
> Suggestions and additions welcome.
How about:
Q. What does "valid" mean, and what sort of problems does the Markup
Validator <em>not</em> find?
A. HTML is an application of SGML, a generalised system for creating
markup languages. SGML markup languages are defined by what is known
as a DTD - a computer-readable description of the features of that
markup language. If the Markup Validator tells you that your document
is "valid", this means that it complies in all respects with the rules
as defined in the DTD you are using.
However, some features of HTML are not able to be described in a DTD.
For example, the following tag is valid under the HTML 4.01
Transitional DTD:
<font color="mauve">
Although it is valid under the DTD, it is not correct HTML since the
text of the HTML specification does not allow "mauve" as the value
for the "color" attribute.
It is therefore possible for your documents to validate but still
not be correct HTML. The Markup Validator is nevertheless a very
useful tool for helping you to ensure that your HTML documents
comply with specifications and are usable by the maximum number of
users.
Received on Tuesday, 23 November 2004 14:31:53 UTC