When non-nil this does two things:
First it loads the reverse-pointers-code module. This can be used to check what things to keep in the image. If you need documentation for reverse-pointers-code, please contact Lisp Support.
Secondly it sets the image up such that calling the application with command line argument -interrogate-symbols, before starting the application, allows you to interrogate-symbols. See Interrogate-Symbols.
LispWorks Delivery User Guide - 15 Feb 2015