- From: Harvey Bingham <hbingham@acm.org>
- Date: Mon, 02 Apr 2001 00:20:52 -0400
- To: w3c-wai-er-ig@w3.org
- Cc: wai-xtech@w3.org
Summary: In August 2000 I explored the use of the class="..." attribute within WAI guideline, technique, and checkpoint list documents of WCAG, AT, UA, and ER at that time. A small set of values for class="value" are included in the default.css used for WAI documents. The documents studied include many more values. A new class="value" presumably is added by an author to make a useful distinction for the user. Such addition may require an augmented stylesheet to describe what to do with it. Any attempt by a user of assistive technology will need to know how to recognize the author's reason for such class values, and distinguish among those that are significant. That is asking a lot from the assistive technology. Few class values are explicitly included in the html head of the WAI documents. I believe there are many more class values identified than are included in the default WAI css stylesheet. I also noted some attribute values were unquoted, and some name case variations appear. These are inappropriate for moving forward to either XHTML or any XML application. Motivation: At 2000-08-18 15:58-0400, Leonard R. Kasday wrote: >I had an action item from the last telecon on writing up a straw proposal >on <em>making classes accessible</em>. They are posted at > >http://www.w3.org/WAI/ER/IG/classuse.html > >Two questions: > >1. Would this be of practical value? >2. Is is philosophically acceptable? Len's points include the confounding of class values for presentation guidance on a set of elements, with alternative use by user agents. He notes that title is an alternative for description. He describes association of title value with class value. Results: The list of class attribute values is larger than the 14 values that Len Kasday had indicated. The semantics for several are not suggested by their names. I wonder if CSS support for these documents covers all of them? Many are missing in the default.css provided with WCAG at that time. [# Today (2001-04-01 I checked for any local class definitions in <style>...</style> in the html document heads. The few found are noted below.] For each of the documents of the working groups, I show the total count of class="value" followed by the counts for each of the distinct values. I use a two-letter code for each document in each set. That allows some intra-document comparisons. 1. Summary of class attribute values in WCAG htm files Count Code Filename 93 cl cl990505.htm WCAG Checklist 537 te te990505.htm WCAG Checklist table form 363 wc wc990505.htm WCAG 1.0 Count Codes Class 12 te ainst # 16 cl checkhead # 65 cl checkinfo 301 te wc checkpoint 3 wc CHECKPOINT 28 te wc checkpoints 1 wc conform 3 cl te wc copyright 9 te css-example 9 te deprecated-example 40 wc dfn-instance 1 te dropcap 42 te einst 50 te example 16 wc GLOSSARY 53 wc glossary 14 wc guideline 3 cl te wc head 1 te nav 12 cl te wc navbar 1 te navigation-bar 1 te newbullet 15 te wc nonb 17 te wc noprint 9 cl te wc notoc 103 te wc noxref 57 te off 5 te quicktest 2 te section2 14 wc subhead # 3 cl table 12 te wc toc 24 te wc tocline2 51 te wc tocline3 993 Total class occurrences, 34 different class values. # Local style for use in table row and in div (unlisted above) to center table. 2. Summary of class attribute values in htm files for ATAG Count Code Filename 182 at atag10.htm Authoring Tool Accessibility Guidelines 1.0 40 cl clatag10.htm ATAG Checklist 76 ct ctatag10.htm ATAG Checklist Table 419 tc tcatag10.htm ATAG Techniques Count Codes Class # 4 ct checkhead # 28 ct checkinfo 144 at tc checkpoint 14 at tc checkpoints 2 at tc conform 4 at cl ct tc copyright 82 at tc dfn-instance 2 at tc glossary 14 at tc guideline 4 at cl ct tc head 16 at cl ct tc navbar 11 at tc nonb 32 at tc noprint 28 at cl ct tc notoc 51 at cl ct tc noxref 1 at priorities-specific 49 at cl ct tc priority1 53 at cl ct tc priority2 31 at cl ct tc priority3 22 at cl ct tc priorityR # 4 ct table 74 tc techniques 1 tc technologies 9 at tc toc 15 at tc tocline2 22 at tc tocline3 717 Total class occurrences, 26 different class values. # Local style for use in table row and in div (unlisted above) to center table. 3. Summary of class attribute values in htm files for User Agent Guidelines Count Code Filename 13 cl clua.htm User Agent checklist 114 ct ctua.htm User Agent checklist table 689 ua ua10610.htm User Agent Guidelines 2000-06-10 Count Codes Class # 14 ct checkhead # 84 ct checkinfo 118 ua checkpoint 19 ua checkpoints 3 cl ct ua copyright 195 ua dfn-instance 86 ua glossary 4 ua GLOSSARY 11 ua guideline 11 ua guideline-box 3 cl ct ua head 12 cl ct ua navbar 2 ua nonb 87 ua noprint 9 cl ct ua notoc 52 cl ct ua noxref 33 cl ct ua priority1 24 cl ct ua priority2 12 cl ct ua priority3 11 ua subhead 3 ct table 4 ua toc 4 ua tocline2 11 ua tocline3 4 ua tocxref 816 Total class occurrences, 25 different class values. # have local <style tr:checkhead ...> and <style tr:checkinfo ...> 4. Summary of class attribute values in htm file for ERT working draft Count Code Filename 75 er ert00823.htm ERT 2000-08-23 working draft Count Codes Class 1 er copyright 7 er E 1 er head 4 er navbar 2 er notoc 2 er toc 29 er tocline2 29 er tocxref 75 Total class occurrences, 8 different class values. 5. Element and Attribute Name Capitalization I also note inconsistent use of capitalization. Upper-case element names are used in the WCAG checklist and the table version of it. A mixture, some capitalized, some not, are used in WCAG. In ERT, most, but not all tags are uppercase, with inconsistency in individual tags (for example <a ...> and <A ...>.) I suggest that as we move toward XHTML or XML, we should use lower-case element type names and attribute names. We certainly should avoid a mixture. 6. Attribute Name Quoting XML and XHTML require that all attribute values must be quoted, either by matching "..." or '...'. That has not been consistently used in the WAI html documents. Regards/Harvey Bingham hbingham@acm.org Invited Expert, W3C Web Accessibility Initiative
Received on Monday, 2 April 2001 01:08:25 UTC