-Displays all pools formatted using a different \fBZFS\fR on-disk version. Older versions can continue to be used, but some features may not be available. These pools can be upgraded using "\fBzpool upgrade -a\fR". Pools that are formatted with a more recent version are also displayed, although these pools will be inaccessible on the system.
+Displays pools which do not have all supported features enabled and pools formatted using a legacy ZFS version number. These pools can continue to be used, but some features may not be available. Use "\fBzpool upgrade -a\fR" to enable all features on all pools.