-can also used to clear the keyring of all the keys.
-This is useful when all the mappings have failed to due to an DNS outage
-or some other error resulting in all the cached uid/gid to be invalid.
+can also used to clear the keyring of all the keys or
+revoke one particular key.
+This is useful when the id mappings have failed to due
+to a lookup error resulting in all the cached uids/gids to be set
+to the user id nobody.