+.BI "\-r," "" " \-\-reverse\-lookup"
+mountd tracks IP addresses in the rmtab, and when a DUMP request is made (by
+someone running showmount -a, for instance), it returns IP addresses instead
+of hostnames by default. This option causes mountd to do a reverse
+lookup on each IP address and return that hostname instead. Enabling this can
+have a substantial negative effect on performance in some situations.
+.TP
+.BR "\-t N" " or " "\-\-num\-threads=N"
+This option specifies the number of worker threads that rpc.mountd
+spawns. The default is 1 thread, which is probably enough. More
+threads are usually only needed for NFS servers which need to handle
+mount storms of hundreds of NFS mounts in a few seconds, or when
+your DNS server is slow or unreliable.
+.TP