<long-desc>
Long Description
Full description or summary of the content of an object such as a graphic, table,
figure, or text box.
Remarks
The long description is a non-visual element used by systems such as pronouncing
screen readers to make the object accessible to people or systems that cannot
read/see/display the object.
Long Description Contents: This element was
originally designed to contain a description, but some
newer systems expect this element to contain a URI that points to such a description. Best
practice is to incorporate a textual description, including or ending with an untagged
URI, and repeat the URI in the @xlink:href
attribute so that a link can be made.
Accessibility: Please reserve this tag for accessibility uses such as pronouncing screen
readers. The <long-desc> is not a visual
element; rather, its purpose is to be spoken in circumstances where the visual form of the
object cannot be viewed. This element differs from the <alt-text> element in both length and purpose. The
<alt-text> is typically very short, for quick
scan reading by a screen reader or showing as words behind a graphic. The <long-desc>
is meant for an extended description of an object such as a figure, table, graphic, etc.,
for example, a textual summary of a pie chart that explains both the visual form of the
chart and significance of its findings.
Best Practice: The <long-desc> element should not to be used as a replacement for <caption>, which is a visual element typically displayed alongside a figure, table,
etc. Thus <long-desc> should not be used to
hold supplementary data. The <long-desc> is
not a visual element.
Attributes
Content Model
<!ELEMENT long-desc (#PCDATA %long-desc-elements;)* >
Expanded Content Model
(#PCDATA | x)*
Description
Any combination of:
- Text, numbers, or special characters
- <x> X - Generated Text and Punctuation
This element may be contained in:
Example
...
<table-wrap>
<caption>
<title>The Size/Price Paradox</title>
</caption>
<long-desc>Table is a price comparison of some
unknown objects that are identified only by color as
Red and Green. The price of small, medium, and
large objects is given for each color, with Green
objects getting cheaper with increasing size, from
$3.25 for small to $2.25 for medium to $1.15 for
large. In contrast, Red objects get more expensive
with size, with small costing $3.25, medium for $5.25,
and large for $9.95.</long-desc>
<table rules="rows">
<thead>
<tr>
<th>Color</th>
<th>Size</th>
<th>Price</th>
</tr>
</thead>
<tbody>
<tr>
<td rowspan="3">Green</td>
<td>small</td>
<td>$3.25</td>
</tr>
<tr>
<td>medium</td>
<td>$2.25</td>
</tr>
<tr>
<td>large</td>
<td>$1.15</td>
</tr>
<tr>
<td rowspan="3">Red</td>
<td>small</td>
<td>$3.25</td>
</tr>
<tr>
<td>medium</td>
<td>$5.25</td>
</tr>
<tr>
<td>large</td>
<td>$9.95</td>
</tr>
</tbody>
</table>
</table-wrap>
...