lost desktop reveal icon

[Gary Kirkpatrick]

I am using 9.1 remix.  This version includes an multi-colored icon
that shows you the various options e.g. favorites, accessories,
internet, office, system etc.  Programs open in full display mode so
in order to reach these opens you click this icon.  The option is to
right click on a window and choose minimize or unmaximize.

This icon went missing and is not included among those you choose to
add to panel.  Anyone know how to retrive this icon?

Thanks

gary