For output generated
with the GIF, JPG, PNG, ACTXIMG, and JAVAIMG device drivers, using
the ALTDESC graphics option displays the chart description, and is
set by default.
The NOALTDESC graphics
option suppresses the display of the chart description.
provides content to the ALT attribute of your HTML file and replaces
the default chart description content. The description value is limited
to 256 characters. Chart descriptions are not supported in presentations
generated by the ActiveX, Java, and JAVAMETA device drivers.
DESCRIPTION=" " can also
be used to suppress the chart description.