diff --git a/xCAT-client/pods/man1/rnetboot.1.pod b/xCAT-client/pods/man1/rnetboot.1.pod
index 0a89cfe78..2be5f2866 100644
--- a/xCAT-client/pods/man1/rnetboot.1.pod
+++ b/xCAT-client/pods/man1/rnetboot.1.pod
@@ -29,7 +29,7 @@ Force reboot the system no matter what state the node is.  By default, rnetboot
 
 B<-f>          
 
-Force immediate shutdown of the partition.
+Force immediate shutdown of the partition. This flag must be used with -D flag.
 
 B<-m>