Remember the ALT attribute in IMG tags? The SUMMARY attribute in TABLE tags serve a similar purpose, in that it will provide a description of the table to users of non-visual browsers. Unlike the ALT tag, Explorer 4.x, Communicator 4.x and lower browsers do not use the SUMMARY tag to display pop-up hints when the mouse is paused over the table.
NOTE: You may not see a visual change by adding the SUMMARY attribute if you're using a graphical browser. However, HTML authors concerned about their content being accessible in different mediums and users with disabilities, for example, are advised to use provide a summary of the table.
Following is an example of a table with the SUMMARY attribute defined.
HTML code used to create the above table:
<table
SUMMARY="Red, green and blue rectangles"
border=1>
<tr>
<td bgcolor=red> </td>
<td bgcolor=green> </td>
<td bgcolor=blue> </td>
</tr>
</table>
Listing #2 : HTML code. Download summary (0.24 KB).
TIP: Use the TITLE attribute for tables to create pop-up hints containing descriptions you provide.
W3C - HyperText Markup Language
Current HTML recommendations from the World Wide Web Consortium.
Listing #1 : HTML References