- From: Leonard R. Kasday <kasday@acm.org>
- Date: Tue, 10 Aug 1999 11:12:49 -0400
- To: wai-wcag-editor@w3.org
- Cc: w3c-wai-er-ig@w3.org
Hi wcag, (copied to er-ig) Any word on our questions about null or alt text http://lists.w3.org/Archives/Public/w3c-wai-er-ig/1999Jun/0050.html We need this for this for the ER techniques document that Chris is editing at http://aprompt.snow.utoronto.ca/docs/Implementation.html I edited that email a bit here to frame it as a set of explicit questions, labeled a thru g. -------------------- This includes the term null alt text to mean ALT="" i.e. quote quote and blank alt text to mean ALT=" " i.e. quote space quote. Our first questions are about Technique 5.6.1. http://www.w3.org/TR/WAI-WEBCONTENT-TECHS/#style-alignment It was interpreted to mean that blank alt text " " is forbidden but null alt text "" is allowed. Several people pointed out that blank alt text is not good HTML: browers are allowed to ignore leading and trailing space, and in fact the HTML spec says that it "should" not be used. However, it was argued that these guidelines should only address things that impact accessibility. [However, 5.6.1 doesn't explicitly forbid blank alt text. All it says is that "Authors should not use spaces for the value of "alt" to prevents the words from running together when the image is not loaded". So first of all, it only applies to this special case. Also, the example is alt=" " which is an entirely different thing]. So the first questions to WCAG are: a. Is blank alt text " " forbidden always? If so Why? b. Is blank alt text " " forbidden for purposes of spacing text apart? If so, why? c. Is " " forbidden always? If so, Why? d. Is " " forbidden for purposes of spacing text apart? If so, Why? Another suggestion was that blank alt text be used for spacers " " because that coveys the meaning of a space. Objections to this were the "bad HTML" argument used above, and also that it contradicts 5.6.1. In your document, in the deprecaed [put presumably allowable] example in 5.6.1, "spacer" is used for alt text of a spacer element. There was objection this since it was felt to just clutter up speech [and contractions the recommendation of using null alt text earlier in 5.6.1]. Question e: what to use for spacers? The following applies to checkpoint 13.1 which requires meaningful text in a link Suggestion to WCAG: allow null alt text in links in certain circumstances, per following rules: If the image is the only item in the link and there is no other usable link to that item on the page, then neither null or blank alt text is allowed. for example, <A href="foo.html"> <img alt="" src=...> </A> is illegal if no other link on the page points to foo.html. However, if usable text or image with meaningful alt text is included in the link, then null alt text is allowed. E.g. the following are legal. <A href="foo.html"> <img alt="" src=...> prices </A> <A href="foo.html"> <img alt="prices" ...><img alt="" src=...> </A> Question f: Do you agree with the above rule? There's another situation on which so far at least we didn't reach consensus: the case where an image and text which are visually adjacent point to the same url. Examples are images which are bullets or images, as in www.whitehouse.gov. This is very common on the web. Sometimes these pages can be rewritten to give a similar visual appearance with image and text as part of the same link, but this may not always be possible, e.g. if tables are used for layout. It was suggested that null alt text be allowed in such cases for the image to avoid tiresome redundancy where every link gets spoken twice. On the other hand, it was argued that some browsers would reveal that there's a link there, e.g. lynx with certain options such as lynx -number_links -hiddenlinks=merge [or using the l command]. [possibly also browsers like pwwebspeak or home page reader] It was argued that a user would lose confidence in the pages accessibility to hear links without ALT text. On the other hand, [under some circumstances] the links would be invisible, and could can be switched off at users discretion, in some cases by turning off speaking pronunciation [or by turning off the lynx options mentioned above]. Question g to WCAG: to allow or not allow null alt text for this circumstance. ------- Leonard R. Kasday, Ph.D. Universal Design Engineer, Institute on Disabilities/UAP, and Adjunct Professor, Electrical Engineering Temple University Ritter Hall Annex, Room 423, Philadelphia, PA 19122 kasday@acm.org (215) 204-2247 (voice) (800) 750-7428 (TTY)
Received on Tuesday, 10 August 1999 11:10:05 UTC