A list of package names for which their external symbols should be shaken when the value of :shake-externals is
nil
. When the value of :shake-externals is
t
(the default), this keyword has no effect.
The externals of the
keyword
package are always shaken, regardless of the value of
:packages-to-shake-externals
.
LispWorks Delivery User Guide - 13 Dec 2011