The only thing I can think to add is that there's also an "INDEX"
 option.  It sends out an posting with a list of the "Subjects:"
 posted during the digest period, and also a boilerplate LISTSERV
 job to retrieve the articles that you may be interested in.  It's
 quite nice!  People can just select the articles they want rather
 than receive everything that's posted.  The command used to choose
 that form of subscription is (not surprisingly),  SET XXXX-L INDEX
 
 -jj