For an image that presents important information (i.e. a chart, table, or diagram) it
is sometimes necessary to provide a detailed description of the image's content that
supplements its alternative text. This description can be included in the text of the main
web page, or it can be placed in a separate page for this purpose and referenced by the
"longdesc" attribute of the IMG element. For example,
<IMG SRC="chart.gif" ALT="Chart of cash flow for each month"
LONGDESC="http://www.thismachine.com/cashflowchar.txt">
Most current web browsers do not yet support the "longdesc" attribute. In order
to provide for both the present and the future, we recommend using both the
"longdesc" attribute and following the image by a descriptive (or D) link:
<IMG SRC="chart.gif" ALT="Chart of cash flow for each month"
LONGDESC="http://www.thismachine.com/cashflowchar.txt">
<A HREF="cashflowchar.txt">D</A> Rationale:
This is important for users who have turned off image-loading in their web browsers,
those using text-based browsers like Lynx, and people who are blind and require the use of
a screen reader to read the contents of the screen for them. |
