diff --git a/components/cache.rst b/components/cache.rst
index b4faad6af41..d728f4455e0 100644
--- a/components/cache.rst
+++ b/components/cache.rst
@@ -63,24 +63,24 @@ instantiate :class:`Symfony\\Component\\Cache\\Simple\\FilesystemCache`::
 Now you can create, retrieve, update and delete items using this object::
 
     // save a new item in the cache
-    $cache->set('stats.num_products', 4711);
+    $cache->set('stats.products_count', 4711);
 
     // or set it with a custom ttl
-    // $cache->set('stats.num_products', 4711, 3600);
+    // $cache->set('stats.products_count', 4711, 3600);
 
     // retrieve the cache item
-    if (!$cache->has('stats.num_products')) {
+    if (!$cache->has('stats.products_count')) {
         // ... item does not exists in the cache
     }
 
     // retrieve the value stored by the item
-    $numProducts = $cache->get('stats.num_products');
+    $productsCount = $cache->get('stats.products_count');
 
     // or specify a default value, if the key doesn't exist
-    // $numProducts = $cache->get('stats.num_products', 100);
+    // $productsCount = $cache->get('stats.products_count', 100);
 
     // remove the cache key
-    $cache->delete('stats.num_products');
+    $cache->delete('stats.products_count');
 
     // clear *all* cache keys
     $cache->clear();
@@ -88,18 +88,18 @@ Now you can create, retrieve, update and delete items using this object::
 You can also work with multiple items at once::
 
     $cache->setMultiple(array(
-        'stats.num_products' => 4711,
-        'stats.num_users' => 1356,
+        'stats.products_count' => 4711,
+        'stats.users_count' => 1356,
     ));
 
     $stats = $cache->getMultiple(array(
-        'stats.num_products',
-        'stats.num_users',
+        'stats.products_count',
+        'stats.users_count',
     ));
 
     $cache->deleteMultiple(array(
-        'stats.num_products',
-        'stats.num_users',
+        'stats.products_count',
+        'stats.users_count',
     ));
 
 Available Simple Cache (PSR-16) Classes
@@ -162,22 +162,22 @@ a filesystem-based cache, instantiate :class:`Symfony\\Component\\Cache\\Adapter
 Now you can create, retrieve, update and delete items using this cache pool::
 
     // create a new item by trying to get it from the cache
-    $numProducts = $cache->getItem('stats.num_products');
+    $productsCount = $cache->getItem('stats.products_count');
 
     // assign a value to the item and save it
-    $numProducts->set(4711);
-    $cache->save($numProducts);
+    $productsCount->set(4711);
+    $cache->save($productsCount);
 
     // retrieve the cache item
-    $numProducts = $cache->getItem('stats.num_products');
-    if (!$numProducts->isHit()) {
+    $productsCount = $cache->getItem('stats.products_count');
+    if (!$productsCount->isHit()) {
         // ... item does not exists in the cache
     }
     // retrieve the value stored by the item
-    $total = $numProducts->get();
+    $total = $productsCount->get();
 
     // remove the cache item
-    $cache->deleteItem('stats.num_products');
+    $cache->deleteItem('stats.products_count');
 
 For a list of all of the supported adapters, see :doc:`/components/cache/cache_pools`.
 
diff --git a/components/cache/adapters/doctrine_adapter.rst b/components/cache/adapters/doctrine_adapter.rst
index 98580a9dbf5..f8f95126ae9 100644
--- a/components/cache/adapters/doctrine_adapter.rst
+++ b/components/cache/adapters/doctrine_adapter.rst
@@ -20,7 +20,7 @@ third parameters::
 
     $provider = new SQLite3Cache(new \SQLite3(__DIR__.'/cache/data.sqlite'), 'youTableName');
 
-    $symfonyCache = new DoctrineAdapter(
+    $cache = new DoctrineAdapter(
 
         // a cache provider instance
         CacheProvider $provider,
diff --git a/components/cache/adapters/php_array_cache_adapter.rst b/components/cache/adapters/php_array_cache_adapter.rst
index c2c722eae3f..716a0abd75e 100644
--- a/components/cache/adapters/php_array_cache_adapter.rst
+++ b/components/cache/adapters/php_array_cache_adapter.rst
@@ -15,8 +15,8 @@ that is optimized and preloaded into OPcache memory storage::
     if ($needsWarmup) {
         // some static values
         $values = array(
-            'stats.num_products' => 4711,
-            'stats.num_users' => 1356,
+            'stats.products_count' => 4711,
+            'stats.users_count' => 1356,
         );
 
         $cache = new PhpArrayAdapter(
@@ -29,7 +29,7 @@ that is optimized and preloaded into OPcache memory storage::
     }
 
     // ... then, use the cache!
-    $cacheItem = $cache->getItem('stats.num_users');
+    $cacheItem = $cache->getItem('stats.users_count');
     echo $cacheItem->get();
 
 .. note::
diff --git a/components/cache/cache_items.rst b/components/cache/cache_items.rst
index b534721859e..73410ea2c54 100644
--- a/components/cache/cache_items.rst
+++ b/components/cache/cache_items.rst
@@ -31,21 +31,21 @@ Cache items are created with the ``getItem($key)`` method of the cache pool. The
 argument is the key of the item::
 
     // $cache pool object was created before
-    $numProducts = $cache->getItem('stats.num_products');
+    $productsCount = $cache->getItem('stats.products_count');
 
 Then, use the :method:`Psr\\Cache\\CacheItemInterface::set` method to set
 the data stored in the cache item::
 
     // storing a simple integer
-    $numProducts->set(4711);
-    $cache->save($numProducts);
+    $productsCount->set(4711);
+    $cache->save($productsCount);
 
     // storing an array
-    $numProducts->set(array(
+    $productsCount->set(array(
         'category1' => 4711,
         'category2' => 2387,
     ));
-    $cache->save($numProducts);
+    $cache->save($productsCount);
 
 The key and the value of any given cache item can be obtained with the
 corresponding *getter* methods::
diff --git a/components/filesystem.rst b/components/filesystem.rst
index 15077ee2fc1..0747270c08e 100644
--- a/components/filesystem.rst
+++ b/components/filesystem.rst
@@ -225,10 +225,10 @@ The :method:`Symfony\\Component\\Filesystem\\Filesystem::readlink` method provid
 by the Filesystem component always behaves in the same way::
 
     // returns the next direct target of the link without considering the existence of the target
-    $fs->readlink('/path/to/link');
+    $fileSystem->readlink('/path/to/link');
 
     // returns its absolute fully resolved final version of the target (if there are nested links, they are resolved)
-    $fs->readlink('/path/to/link', true);
+    $fileSystem->readlink('/path/to/link', true);
 
 Its behavior is the following::
 
@@ -304,7 +304,7 @@ appendToFile
 :method:`Symfony\\Component\\Filesystem\\Filesystem::appendToFile` adds new
 contents at the end of some file::
 
-    $fs->appendToFile('logs.txt', 'Email sent to user@example.com');
+    $fileSystem->appendToFile('logs.txt', 'Email sent to user@example.com');
 
 If either the file or its containing directory doesn't exist, this method
 creates them before appending the contents.
diff --git a/components/ldap.rst b/components/ldap.rst
index cfc4f78e8ec..743380d7179 100644
--- a/components/ldap.rst
+++ b/components/ldap.rst
@@ -118,19 +118,19 @@ delete existing ones::
         'objectClass' => array('inetOrgPerson'),
     ));
 
-    $em = $ldap->getEntryManager();
+    $entityManager = $ldap->getEntryManager();
 
     // Creating a new entry
-    $em->add($entry);
+    $entityManager->add($entry);
 
     // Finding and updating an existing entry
     $query = $ldap->query('dc=symfony,dc=com', '(&(objectclass=person)(ou=Maintainers))');
     $result = $query->execute();
     $entry = $result[0];
     $entry->setAttribute('email', array('fabpot@symfony.com'));
-    $em->update($entry);
+    $entityManager->update($entry);
 
     // Removing an existing entry
-    $em->remove(new Entry('cn=Test User,dc=symfony,dc=com'));
+    $entityManager->remove(new Entry('cn=Test User,dc=symfony,dc=com'));
 
 .. _Packagist: https://packagist.org/packages/symfony/ldap
diff --git a/components/routing.rst b/components/routing.rst
index a765977d478..b7d10117b9c 100644
--- a/components/routing.rst
+++ b/components/routing.rst
@@ -413,8 +413,8 @@ routes with UTF-8 characters:
         use Symfony\Component\Routing\RouteCollection;
         use Symfony\Component\Routing\Route;
 
-        $collection = new RouteCollection();
-        $collection->add('route1', new Route('/category/{name}',
+        $routes = new RouteCollection();
+        $routes->add('route1', new Route('/category/{name}',
             array(
                 '_controller' => 'AppBundle:Default:category',
             ),
@@ -426,7 +426,7 @@ routes with UTF-8 characters:
 
         // ...
 
-        return $collection;
+        return $routes;
 
 In this route, the ``utf8`` option set to ``true`` makes Symfony consider the
 ``.`` requirement to match any UTF-8 characters instead of just a single
@@ -494,8 +494,8 @@ You can also include UTF-8 strings as routing requirements:
         use Symfony\Component\Routing\RouteCollection;
         use Symfony\Component\Routing\Route;
 
-        $collection = new RouteCollection();
-        $collection->add('route2', new Route('/default/{default}',
+        $routes = new RouteCollection();
+        $routes->add('route2', new Route('/default/{default}',
             array(
                 '_controller' => 'AppBundle:Default:default',
             ),
@@ -509,7 +509,7 @@ You can also include UTF-8 strings as routing requirements:
 
         // ...
 
-        return $collection;
+        return $routes;
 
 .. tip::
 
diff --git a/console/lazy_commands.rst b/console/lazy_commands.rst
index b05e17009e0..497b3cd33a0 100644
--- a/console/lazy_commands.rst
+++ b/console/lazy_commands.rst
@@ -71,13 +71,13 @@ with command names as keys and service identifiers as values::
     use Symfony\Component\Console\CommandLoader\ContainerCommandLoader;
     use Symfony\Component\DependencyInjection\ContainerBuilder;
 
-    $container = new ContainerBuilder();
-    $container->register(FooCommand::class, FooCommand::class);
-    $container->compile();
+    $containerBuilder = new ContainerBuilder();
+    $containerBuilder->register(FooCommand::class, FooCommand::class);
+    $containerBuilder->compile();
 
-    $commandLoader = new ContainerCommandLoader($container, array(
+    $commandLoader = new ContainerCommandLoader($containerBuilder, array(
         'app:foo' => FooCommand::class,
     ));
 
 Like this, executing the ``app:foo`` command will load the ``FooCommand`` service
-by calling ``$container->get(FooCommand::class)``.
+by calling ``$containerBuilder->get(FooCommand::class)``.
diff --git a/doctrine.rst b/doctrine.rst
index 0bd4b9c5e5a..cb43023746e 100644
--- a/doctrine.rst
+++ b/doctrine.rst
@@ -504,7 +504,7 @@ a controller, this is pretty easy. Add the following method to the
     public function createAction()
     {
         // you can fetch the EntityManager via $this->getDoctrine()
-        // or you can add an argument to your action: createAction(EntityManagerInterface $em)
+        // or you can add an argument to your action: createAction(EntityManagerInterface $entityManager)
         $entityManager = $this->getDoctrine()->getManager();
 
         $product = new Product();
@@ -525,8 +525,8 @@ a controller, this is pretty easy. Add the following method to the
     public function editAction()
     {
         $doctrine = $this->getDoctrine();
-        $em = $doctrine->getManager();
-        $em2 = $doctrine->getManager('other_connection');
+        $entityManager = $doctrine->getManager();
+        $otherEntityManager = $doctrine->getManager('other_connection');
     }
 
 .. note::
diff --git a/event_dispatcher/method_behavior.rst b/event_dispatcher/method_behavior.rst
index 70cd455cdb0..ffd58b25d9c 100644
--- a/event_dispatcher/method_behavior.rst
+++ b/event_dispatcher/method_behavior.rst
@@ -121,10 +121,10 @@ could listen to the ``mailer.post_send`` event and change the method's return va
     {
         public function onMailerPostSend(AfterSendMailEvent $event)
         {
-            $ret = $event->getReturnValue();
-            // modify the original ``$ret`` value
+            $returnValue = $event->getReturnValue();
+            // modify the original ``$returnValue`` value
 
-            $event->setReturnValue($ret);
+            $event->setReturnValue($returnValue);
         }
 
         public static function getSubscribedEvents()
diff --git a/form/create_custom_field_type.rst b/form/create_custom_field_type.rst
index cd1a360ed87..c62928c3632 100644
--- a/form/create_custom_field_type.rst
+++ b/form/create_custom_field_type.rst
@@ -297,14 +297,14 @@ add a ``__construct()`` method like normal::
 
     class ShippingType extends AbstractType
     {
-        private $em;
+        private $entityManager;
 
-        public function __construct(EntityManagerInterface $em)
+        public function __construct(EntityManagerInterface $entityManager)
         {
-            $this->em = $em;
+            $this->entityManager = $entityManager;
         }
 
-        // use $this->em down anywhere you want ...
+        // use $this->entityManager down anywhere you want ...
     }
 
 If you're using the default ``services.yml`` configuration (i.e. services from the
diff --git a/form/form_dependencies.rst b/form/form_dependencies.rst
index 873c94ad864..080af486b83 100644
--- a/form/form_dependencies.rst
+++ b/form/form_dependencies.rst
@@ -36,11 +36,11 @@ create your form::
     // ...
     public function newAction()
     {
-        $em = $this->getDoctrine()->getManager();
+        $entityManager = $this->getDoctrine()->getManager();
 
         $task = ...;
         $form = $this->createForm(TaskType::class, $task, array(
-            'entity_manager' => $em,
+            'entity_manager' => $entityManager,
         ));
 
         // ...
diff --git a/security/form_login_setup.rst b/security/form_login_setup.rst
index 52800587f79..ca7a64d28b3 100644
--- a/security/form_login_setup.rst
+++ b/security/form_login_setup.rst
@@ -143,13 +143,13 @@ Great! Next, add the logic to ``loginAction()`` that displays the login form::
     // src/AppBundle/Controller/SecurityController.php
     use Symfony\Component\Security\Http\Authentication\AuthenticationUtils;
 
-    public function loginAction(Request $request, AuthenticationUtils $authUtils)
+    public function loginAction(Request $request, AuthenticationUtils $authenticationUtils)
     {
         // get the login error if there is one
-        $error = $authUtils->getLastAuthenticationError();
+        $error = $authenticationUtils->getLastAuthenticationError();
 
         // last username entered by the user
-        $lastUsername = $authUtils->getLastUsername();
+        $lastUsername = $authenticationUtils->getLastUsername();
 
         return $this->render('security/login.html.twig', array(
             'last_username' => $lastUsername,
@@ -159,9 +159,9 @@ Great! Next, add the logic to ``loginAction()`` that displays the login form::
 
 .. note::
 
-    If you get an error that the ``$authUtils`` argument is missing, it's
-    probably because you need to activate this new feature in Symfony 3.4. See
-    this :ref:`controller service argument note <controller-service-arguments-tag>`.
+    If you get an error that the ``$authenticationUtils`` argument is missing,
+    it's probably because you need to activate this new feature in Symfony 3.4.
+    See this :ref:`controller service argument note <controller-service-arguments-tag>`.
 
 Don't let this controller confuse you. As you'll see in a moment, when the
 user submits the form, the security system automatically handles the form
diff --git a/security/json_login_setup.rst b/security/json_login_setup.rst
index 5483f694c61..3d1c12ffd40 100644
--- a/security/json_login_setup.rst
+++ b/security/json_login_setup.rst
@@ -110,12 +110,12 @@ path:
         use Symfony\Component\Routing\RouteCollection;
         use Symfony\Component\Routing\Route;
 
-        $collection = new RouteCollection();
-        $collection->add('login', new Route('/login', array(
+        $routes = new RouteCollection();
+        $routes->add('login', new Route('/login', array(
             '_controller' => 'AppBundle:Security:login',
         )));
 
-        return $collection;
+        return $routes;
 
 Don't let this empty controller confuse you. When you submit a ``POST`` request
 to the ``/login`` URL with the following JSON document as the body, the security
diff --git a/workflow/usage.rst b/workflow/usage.rst
index c40450f18ea..4e94c47fdd6 100644
--- a/workflow/usage.rst
+++ b/workflow/usage.rst
@@ -168,7 +168,7 @@ what actions are allowed on a blog post::
     // Update the currentState on the post
     try {
         $workflow->apply($post, 'to_review');
-    } catch (LogicException $e) {
+    } catch (LogicException $exception) {
         // ...
     }