A text equivalent
for every non-text element shall be provided (e.g., via "alt", "longdesc",
or in element content).
A person viewing through a screen reader should know
the message that the image is conveying. If the images
are only decorative, then use of an empty tag will suffice.
But when the image contains relevant information, then
a text equivalent in the alt tag should be provided.
Alternatives
to multimedia
Equivalent alternatives
for any multimedia presentation shall be synchronized with
the presentation.
If a video file or an animated flash file is created,
a synchronized audio file should also be created to match
audio with captions and the flow of the animation.
Content without
using style sheets
Documents shall be organized
so they are readable without requiring an associated style
sheet.
Even when a user switches off style sheets, the content
should be readable by the user. Using CSS positioning
attributes is a bad idea because unexpected results
can appear if a user switches off the style sheets.
See example of course with style sheets switched off.
The content is still clearly readable and the only difference
is the lack of formatting and some background images,
which are used only for a decorative purpose.
Accessible
page as a last resort
A text-only page, with
equivalent information or functionality, shall be provided
to make a Web site comply with the provisions of this part,
when compliance cannot be accomplished in any other way.
The content of the text-only page shall be updated whenever
the primary page changes.
If it is not possible to make a page accessible due to
constraints, then provide an accessible text only
page of the same. This is illustrated in the diagram