- From: Charles McCathieNevile <charles@w3.org>
- Date: Wed, 1 Mar 2000 00:00:41 -0500 (EST)
- To: WAI AU Guidelines <w3c-wai-au@w3.org>
A trimmed down version included at the end of this.
There are other WCAG checkpoints that seemed to be relevant. Note that
references to checkpoints or techniques are in fact to WCAG checkpoints/techs
- I think that this should be made explicit in the text, but haven't done
that yet.
Charles
--
Charles McCathieNevile mailto:charles@w3.org phone: +61 (0) 409 134 136
W3C Web Accessibility Initiative http://www.w3.org/WAI
Location: I-cubed, 110 Victoria Street, Carlton VIC 3053
Postal: GPO Box 2476V, Melbourne 3001, Australia
Checkpoints:
1.1 Provide a text equivalent for every non-text element [Priority 1]
Refer also to [1]checkpoint 9.1 and [2]checkpoint 13.10.
[3]Techniques for checkpoint 1.1
HTML
o prompt for longdesc and alt for img elements
o prompt for alt for area elements
o prompt for text transcript for audio objects.
o prompt for collated text transcript for movies.
SVG
Prompt for a title and desc for each g group
SMIL
Prompt for alt, longdesc, a text or textstream object for
audio, image and video objects
1.2 Provide redundant text links for each active region of a
server-side image map. [Priority 1]
Refer also to [4]checkpoint 1.5 and [5]checkpoint 9.1.
[6]Techniques for checkpoint 1.2
HTML
+ Use the same User interface for server and client side image
map creations, including prompting for alternatives for each
region. Use alternatives provided to generate redundant
text-based links for server-side maps.
+ Prompt for text which describes the range and the effect of
possible coordinate entries, and generate an alternative,
form-based entry system.
1.3 [7]Until user agents can automatically read aloud the text
equivalent of a visual track, provide an auditory description
of the important information of the visual track of a
multimedia presentation. [Priority 1]
[8]Techniques for checkpoint 1.3
SMIL
o Prompt the author to provide an audio track that
includes description, if necessary with an alternative
version of the video.
1.4 For any time-based multimedia presentation (e.g., a movie or
animation), synchronize equivalent alternatives (e.g., captions
or auditory descriptions of the visual track) with the
presentation. [Priority 1]
[9]Techniques for checkpoint 1.4
HTML
o Use a format such as SMIL which allows for the inclusion
and synchronisation of equivalent tracks
XML
o Use SMIL timing to synchronise equivalents
1.5 [10]Until user agents render text equivalents for client-side
image map links, provide redundant text links for each active
region of a client-side image map. [Priority 3]
Refer also to [11]checkpoint 1.2 and [12]checkpoint 9.1.
[13]Techniques for checkpoint 1.5
HTML
Use the alt associated with area elements to build a
redundant text navigation bar
2.1 Ensure that all information conveyed with color is also available
without color, for example from context or markup. [Priority 1]
[14]Techniques for checkpoint 2.1
2.2 Ensure that foreground and background color combinations provide
sufficient contrast when viewed by someone having color
deficits or when viewed on a black and white screen.
[Priority 2 for images, Priority 3 for text].
[15]Techniques for checkpoint 2.2
HTML, SVG, CSS
Where only one color has been specified (for example a
background but not foreground) ask the author to specify
(or confirm default) colors for other parts, where
possible from a range that has sufficient contrast.
3.1 When an appropriate markup language exists, use markup rather than
images to convey information. [Priority 2]
Refer also to [16]guideline 6 and [17]guideline 11.
[18]Techniques for checkpoint 3.1
HTML
o Where images are readable through Optical Character
Recognition (OCR) as text, use text with CSS styling.
XHTML, XML
o Where images are readable through Optical Character
Recognition (OCR) as text use SVG
o Where images are recognisable as mathematical content,
use MathML
o Prompt the author to use a markup language for text,
mathematics, etc.
6.2 Ensure that equivalents for dynamic content are updated when the
dynamic content changes. [Priority 1]
[19]Techniques for checkpoint 6.2
HTML
o Where scripts change the src attribute of images, prompt
the author to include changes in the alt attribute or
element content.
SVG, XHTML
o Where SMIL animation is used, prompt the authro to
ensure that desc and title elements are appropriately
updated by hte animation
6.3 Ensure that pages are usable when scripts, applets, or other
programmatic objects are turned off or not supported. If this
is not possible, provide equivalent information on an
alternative accessible page. [Priority 1]
[20]Techniques for checkpoint 6.3
HTML
Ask for equivalents for scripts, and applets, for example
a movie (and collated text transcripts, audio, etc)
6.5 Ensure that dynamic content is accessible or provide an
alternative presentation or page. [Priority 2]
[21]Techniques for checkpoint 6.5
7.1 [22]Until user agents allow users to control flickering, avoid
causing the screen to flicker. [Priority 1]
Note. People with photosensitive epilepsy can have seizures
triggered by flickering or flashing in the 4 to 59 flashes per
second (Hertz) range with a peak sensitivity at 20 flashes per
second as well as quick changes from dark to light (like strobe
lights).
[23]Techniques for checkpoint 7.1
HTML (relying on lowsrc attribute - not in W3C recommendation)
Prompt for a non-animated "lowsrc" version of animated
images.
7.2 [24]Until user agents allow users to control blinking, avoid
causing content to blink (i.e., change presentation at a
regular rate, such as turning on and off). [Priority 2]
[25]Techniques for checkpoint 7.2
7.3 [26]Until user agents allow users to freeze moving content, avoid
movement in pages. [Priority 2]
When a page includes moving content, provide a mechanism within
a script or applet to allow users to freeze motion or updates.
Using style sheets with scripting to create movement allows
users to turn off or override the effect more easily. [27]Refer
also to guideline 8.
[28]Techniques for checkpoint 7.3
8.1 Make programmatic elements such as scripts and applets directly
accessible or compatible with assistive technologies
[Priority 1 if functionality is [29]important and not presented
elsewhere, otherwise Priority 2.]
[30]Refer also to guideline 6.
[31]Techniques for checkpoint 8.1
9.1 Provide client-side image maps instead of server-side image maps
except where the regions cannot be defined with an available
geometric shape. [Priority 1]
Refer also to [32]checkpoint 1.1, [33]checkpoint 1.2, and
[34]checkpoint 1.5.
[35]Techniques for checkpoint 9.1
HTML
Use the same interface for defining areas of client- and
server-side maps, and produce the image as client-side
where possible
11.1 Use W3C technologies when they are available and appropriate for
a task and use the latest versions when supported. [Priority 2]
[36]Techniques for checkpoint 11.1
Raster images (PNG, JPEG, GIF)
o Use RDF to incorporate textual equivalents in image
encodings
Vector images
o Use SVG, and prmpt the author to provide appropriate
title and desc elements for each g element.
11.3 Provide information so that users may receive documents according
to their preferences (e.g., language, content type, etc.)
[Priority 3]
[37]Techniques for checkpoint 11.3
11.4 If, [38]after best efforts, you cannot create an [39]accessible
page, provide a link to an alternative page that uses W3C
technologies, is accessible, has [40]equivalent information (or
functionality), and is updated as often as the inaccessible
(original) page. [Priority 1]
[41]Techniques for checkpoint 11.4
13.2 Provide metadata to add semantic information to pages and sites.
[Priority 2]
[42]Refer also to checkpoint 13.5.
[43]Techniques for checkpoint 13.2
Images
Metadata can be added to most image formats comonly used
on the Web, includin PNG, JPEG, GIF, and SVG. @@Include
link to rdfpic sample tool that does this (source
available too).
14.2 Supplement text with graphic or auditory presentations where they
will facilitate comprehension of the page. [Priority 3]
[44]Refer also to guideline 1.
[45]Techniques for checkpoint 14.2
HTML
Provide libraries of accessible clip art to illustrate
common concepts, or allow the author to build them. See
also ATAG 3.5
References
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Received on Wednesday, 1 March 2000 00:00:42 UTC