+.BI "\-H, " "" " \-\-ha-callout " prog
+Specify a high availability callout program, which will receive callouts
+for all client monitor and unmonitor requests. This allows
+.B rpc.statd
+to be used in a High Availability NFS (HA-NFS) environment. The
+program will be run with 3 arguments: The first is either
+.B add-client
+or
+.B del-client
+depending on the reason for the callout.
+The second will be the name of the client.
+The third will be the name of the server as known to the client.
+.TP