[PATCH v3 3/3] git-submodule: Motivate --record with an example use case

@@ -220,6 +220,14 @@ OPTIONS
 	is not set either, `HEAD` will be recorded.  Because the branch name
 	is optional, you must use the equal-sign form (`-r=<branch>`), not
 	`-r <branch>`.
++
+The recorded setting is not actually used by git; however, some
+external tools and workflows may make use of it.  For example, if the
+upstream branches still exist and you have a recorded branch setting
+for each of your submodules, you can update all of the submodules to
+the current branch tips with:
++
+	git submodule foreach 'git checkout $submodule_branch && git pull'
 
 -f::
 --force::