[CSS21] Inaccessibility of Index to CSS2.1 / Violation of WCAG

The index for CSS2.1


replicates the inaccessibility of the index to CSS2, in that it uses
chapter/section numbers as hyperlinks without so much as a title to
indicate to which entry in the index the repetitious numeric hypertext
points.  The PF WG's designated reviewer stopped counting when he
reached 250 instances of the hyperlink text "1", which only took the
reviewer into the "I" section of the index (specifically, on the target
that hyperlinks to the definition of "<integer>", a fact which was only
discoverable by following the link).

It is impossible to express how frustrating such an experience can be,
and how useless it renders the index to anyone experiencing the page
aurally, tactilely, or through a very restricted viewport.

It also violates the W3C's own Web Content Accessibility Guidelines
(WCAG), upon which all W3C publications have a dependency -- in
particular, Guideline 13, where it states:

13.1 Clearly identify the target of each link. [Priority 2]

Link text should be meaningful enough to make sense when read out
of context -- either on its own or as part of a sequence of links.
Link text should also be terse. For example, in HTML, write
"Information about version 4.3" instead of "click here". In
addition to clear link text, content developers may further clarify
the target of a link with an informative link title (e.g., in HTML,
the "title" attribute).

Techniques for checkpoint 13.1

WCAG 1.0 defines "Link text" as:

The rendered text content of a link.

It is, therefore, the request of the Protocols & Formats working group
that a means of differentiating between repetitive hyperlink text be
implemented by the CSS 2.1 editors.

A sufficient (and highly recommended) repair technique for this problem
can be found in the Techniques document for WCAG 2.0:


which details a repair technique which enables a user to contextualize
and fully understand the meaning and target of repetitive hyperlink
test.  The result would be individualized index items, rather than merely
a repetitious and uninformative listing of links by section/chapter
number ONLY, thus making it possible for the non-visual user to utilize
the index.  This repair technique also has the advantage of
individualizing each hyperlink when the document's hyperlinks are listed
in a list of links, or when one is aurally or tactilely experiencing the

/chair, PFWG

Received on Thursday, 20 December 2007 18:08:41 UTC