RE: Indicating Compliance

In short, they are not testing against the same rules. (It is also worth
noting that section 508 is US legislation and only applies to the US. The W3C
is an international organisation, making documents that are intended to be
useful as standards internationally.)

508 (I think its real name is section 508 of the US Federal Government's
Workplace Rehabilitation Act, but I am Australian so 508 is near enough for
me)  provides a set of requirements to be met by Web content (among other
things) including features such as text alternatives for non text
components, and the ability to skip large groups of links.

W3C HTML 4 validation tests one of two things - either whether a document
meets the syntax rules of HTML 4, or whether it is written according to the
HTML 4 specification. The first test is far more common, since it can be done
by a computer program reliably, and there are several web-based services. The
second requires some human interpretation, and there are, at the finest
levels of detail, ambiguities that can arise so that two different
assessments can be justified for the same content.

There is another W3C Specification, Web Content Accessibility Guidelines.
This has broadly the same aims as the 508 rules, of providing a set of
requirements that can ensure people with disabilities can use Web content.
The W3C Specification was published as a "W3C Recommendation" (something we
hope people will use as a standard) in May 1999, and in the documentation of
the 508 rules there is a discussion of the differences.

In brief summary, 508 is close to level-A conformance (the lowest defined
level of conformance) to Web Content Accessibility Guidelines, although there
are a couple of differences.

For more details, please consult the Web Content Accessibility Guidelines - - and the 508 documentation - - or the summary at


Charles McCN

Someone asked me:

  What exactly are the differences between 508 and W3C/HTML4.0 validation?

Received on Saturday, 13 January 2001 19:57:44 UTC