- From: Jason White <jasonw@ariel.ucs.unimelb.edu.au>
- Date: Thu, 18 Nov 1999 10:20:20 +1100 (EST)
- To: Web Content Accessibility Guidelines <w3c-wai-gl@w3.org>
I agree entirely with Nir's position: it is better to advise authors to use more appropriate techniques, particularly CSS, than to waste time debating the merits of various text equivalents for so-called "spacer images". Since this issue originally arose as a query from the ER working group, our answer should suggest that all uses of null and blank ALT attribute values (alt="" alt=" " and alt=" " etc.) should be flagged as errors, with ALT="" being a more serious error than either of the others. The HTML specification does not determine how user agents will or should render ALT=" ". It may be interpreted as a single-character attribute value, comprising a space, or either leading or trailing white-space, to be ignored during HTML processing, preceded or followed by the empty string. As Nir has pointed out, the rendering of so-called "spacer images" is subject to variation across distinct visual media and among different user agents. The rendering of the text equivalent in these cases is equally undetermined, as the present controversy has shown. In the end, authors who wish to misuse HTML in an attempt to achieve formatting effects run the risk of having their documents rendered in unexpected ways by different user agents and/or in different media. Such practices should be avoided.
Received on Wednesday, 17 November 1999 18:20:55 UTC