Shows the clearinghouses where the directory is replicated.
  The master or the read-only icon next to the clearinghouse

Sorry.  HyperReader cannot reproduce this figure. Sorry.  HyperReader cannot reproduce this figure.   indicates the type of replica:

  The master replica  is the first instance of a specific di-
  rectory in the namespace.  After you make copies of the
  directory, you can designate a different replica as the
  master, if necessary, but only one master replica of each
  directory can exist at a time.

  A read-only replica  is a copy of a directory that is avail-
  able only for looking up information.  DECdns does not
  create, modify, or delete names in read-only replicas; it
  simply updates them with changes made to the master
  replica. Read-only replicas save resources because DECdns
  does not make changes in them, nor does it have to gather
  changes from them to disseminate to other replicas.