Noel,
 
    "REG" is  an abbreviation for  "REGISTER".  It takes  one operand,
your name.  Its function is to add an entry to the SIGNUP FILE for the
requesting user with  the requested name.  That name will  then be put
on  all mail  sent  to the  user (except  from  lists they're  already
subscribed to).   It's a handy way  of changing your default  name, or
setting one  if you're  not on any  lists at that  server (I'm  on the
LISTSERV Coordination Board, so I get  mail from every LISTSERV in the
world, most of whom I have no  regular traffic with.  If I want, I can
have a different name at each one, by sending a REGISTER command.)
 
    I  guess  this  is  another   one  that  hasn't  appeared  in  the
documentation yet.  I believe it was added in 1.5f or so.
 
Ross