Got the answers from Eric on this.  Here is my understanding.
 
If a list has a matching filelist, then the FAC of OWN will let the
owner update the filelist using the list password.
 
If the filelist is an orphan, i.e. is not related to a distibution list,
then the following form of the FAC is useful:
 
*+TRY=OWNER(SPECIAL),PW=(SPECIAL)
 
This says that the owners of the SPECIAL list satisfy the TRY FAC and
that the password of the SPECIAL list will be checked.  This is just
what I needed since I have a WELCOME FILELIST where I store WELCOME
and/or FAREWELL messages for all lists that don't have their own
filelist.