Default value:

(and (not (delivery-value :keep-debug-mode))
     (not (delivery-value :interrogate-symbols))
     (eq (delivery-value :dll-exports) :no))

x86 platforms only: If this is non- nil , the heap is compacted just before the delivered image is saved, with all functions being made static. This usually gives the greatest size reduction in delivery. You may want to leave this until the final delivery if you are using a slow machine on which this operation takes some time.

LispWorks Delivery User Guide - 12 Sep 2005