> - Adding new  subscribers via XEDIT  while LISTSERV is  running: LISTSERV
>   may later claim that the new subscribers  are not on the list. The same
>   applies to changes made to a subscriber's address.
 
You cannot log on to the LISTSERV id and edit the LIST file using the
X command while LISTSERV is running.
 
> - Altering list header keywords via  XEDIT while LISTSERV is running: the
>   changes will not be picked up.
 
You cannot log on to the LISTSERV id and alter the list headers
using the X command while LISTSERV is running.
 
> Does this mean the the owners will not be able to "get the list" and change
> the headers?
 
No.
 
> Or is it for local admins who are setting up lists?
 
No. It means that LISTSERV reads the initial contents of the LIST
files at startup, and if you directly modify the contents of the
file from the LISTSERV console while LISTSERV is running by some
method that does not involve LISTSERV processing the new LIST file, the
changes will not be used and can be overwritten with the
in-memory copy when LISTSERV takes some action on the mailing
list (ie, the next SUBSCRIBE request, etc).