Clicking on Function Description >> changes the view of the Function Call Browser to include more information on the function being browsed. The browser appears as in The Function Call Browser in function description mode
Figure 14.2 The Function Call Browser in function description mode
Two further panes appear. Note that the function description button has now changed to Function Description << and that clicking on it restores the view of the Function Call Browser
The extra panes are a function description area, and a documentation area.
LispWorks IDE User Guide (Windows version) - 25 Nov 2011