It refers to the same thing -  to avoid endless loops with other servers,
LISTSERV stops processing requests after  a certain number of consecutive
errors. That  can happen to  a user, although  most people will  think of
sending  a HELP  command  when they  are  lost and  this  will reset  the
counter. Once a user is ignored,  LISTSERV simply throws away any command
he might send without answering. Use the SERVE command to restore access.
 
  Eric