> How does a listowner detect who the concealed memebers are?
 
As has already been said, you can use GET listname (nol  and search
for the flags.  Another way to do it is
 
QUERY listname FOR *@*
 
This will give you a listing of all subscribers, concealed or not,
with a listing of how all the options are set.  You can then use a
search program (a simple one, as available with most mail editors,
works just fine) to find all those with Conceal= Yes.
 
       Douglas Winship   Hays County, Texas  [log in to unmask]
                    Secondary AUTOCAT Listowner