Updated per @kaloianm review.

Author: Anthony Sansone

source/reference/command/flushRouterConfig.txt

@@ -13,18 +13,25 @@ flushRouterConfig
 .. dbcommand:: flushRouterConfig
 
    :dbcommand:`flushRouterConfig` clears the cached routing table in a
-   :binary:`~bin.mongos` instance. Subsequent :binary:`~bin.mongos`
-   commands update the routing table as routes are needed.
+   :binary:`~bin.mongos` instance. Subsequent commands against that 
+   :binary:`~bin.mongos` will repopulate the routing table cache from 
+   the :term:`config server` as they execute.
 
-   When this command is called, it forces an update when the
-   configuration database holds data that is more recent than the data
-   cached in the :binary:`~bin.mongos` process.
+   Use this command to force the routing table cache to be refreshed 
+   from the :term:`config server` if it contains more recent data. In 
+   most cases, this happens automatically. You should need to run 
+   :dbcommand:`flushRouterConfig` only after :dbcommand:`movePrimary` 
+   has been run.
+
+   .. seealso::
+
+      For when and why :dbcommand:`flushRouterConfig` is run, see 
+      **Considerations** on the :dbcommand:`movePrimary` page.
 
    .. warning::
 
-      Do not modify the config data, except as explicitly
-      documented. A config database cannot typically tolerate manual
-      manipulation.
+      Do not modify the routing table data except when it is 
+      explicitly documented.
 
    :dbcommand:`flushRouterConfig` is an administrative command that is
    only available for :binary:`~bin.mongos` instances.