Adding details about a specific version

components/using_components.rst

@@ -27,7 +27,7 @@ Using the Finder Component
     $ composer require symfony/finder
 
 The name ``symfony/finder`` is written at the top of the documentation for
-whatever component you want. 
+whatever component you want.
 
 .. tip::
 
@@ -36,6 +36,12 @@ whatever component you want.
     a ``composer.phar`` file in your directory. In that case, no worries!
     Just run ``php composer.phar require symfony/finder``.
 
+If you know you need a specific version of the library, add that to the command:
+
+.. code-block:: bash
+
+    $ composer require symfony/finder:~2.3
+
 **3.** Write your code!
 
 Once Composer has downloaded the component(s), all you need to do is include