(see guidelines for overcoming access barriers)
For example use the 'longdesc' attribute or provide a 'D' link in HTML. The 'longdesc' attribute in HTML provides a URL to a separate HTML file which has an in-depth description of the image. Make sure that the description is accurate and relevant.
Where browsers don't support 'longdesc', a description link 'D' should be provided. This 'D'-link which is placed next to the image takes users to the same page referred to by the 'longdesc' attribute. A ‘D’ link is visible on the web page, whereas a 'longdesc' is not.
By clicking on the "D" link below the user is taken to a separate page containing a text description of the image. The ‘D’ link is useful for browsers which do not support the 'longdesc' attribute, which are those under Version 6.
<img src="../images/78005.jpg" alt="group collaboration" width="528" height="385" longdesc="longdesc.htm" ><a href="longdesc.htm">d</a>