diff --git a/book/forms.rst b/book/forms.rst
index a4b95fd62c9..d5c969b8d1c 100644
--- a/book/forms.rst
+++ b/book/forms.rst
@@ -1066,7 +1066,7 @@ that will house the logic for building the task form::
 
         public function getName()
         {
-            return 'task';
+            return 'app_task';
         }
     }
 
@@ -1174,7 +1174,7 @@ easy to use in your application.
             app.form.type.task:
                 class: AppBundle\Form\Type\TaskType
                 tags:
-                    - { name: form.type, alias: task }
+                    - { name: form.type, alias: app_task }
 
     .. code-block:: xml
 
@@ -1186,7 +1186,7 @@ easy to use in your application.
 
             <services>
                 <service id="app.form.type.task" class="AppBundle\Form\Type\TaskType">
-                    <tag name="form.type" alias="task" />
+                    <tag name="form.type" alias="app_task" />
                 </service>
             </services>
         </container>
@@ -1200,7 +1200,7 @@ easy to use in your application.
                 'AppBundle\Form\Type\TaskType'
             )
             ->addTag('form.type', array(
-                'alias' => 'task',
+                'alias' => 'app_task',
             ))
         ;
 
diff --git a/cookbook/form/create_custom_field_type.rst b/cookbook/form/create_custom_field_type.rst
index 9a03ef7f501..8a8e0e96e0a 100644
--- a/cookbook/form/create_custom_field_type.rst
+++ b/cookbook/form/create_custom_field_type.rst
@@ -45,7 +45,7 @@ for form fields, which is ``<BundleName>\Form\Type``. Make sure the field extend
 
         public function getName()
         {
-            return 'gender';
+            return 'app_gender';
         }
     }
 
@@ -308,14 +308,14 @@ the ``genders`` parameter value as the first argument to its to-be-created
                 arguments:
                     - '%genders%'
                 tags:
-                    - { name: form.type, alias: gender }
+                    - { name: form.type, alias: app_gender }
 
     .. code-block:: xml
 
         <!-- src/AppBundle/Resources/config/services.xml -->
         <service id="app.form.type.gender" class="AppBundle\Form\Type\GenderType">
             <argument>%genders%</argument>
-            <tag name="form.type" alias="gender" />
+            <tag name="form.type" alias="app_gender" />
         </service>
 
     .. code-block:: php
@@ -329,7 +329,7 @@ the ``genders`` parameter value as the first argument to its to-be-created
                 array('%genders%')
             ))
             ->addTag('form.type', array(
-                'alias' => 'gender',
+                'alias' => 'app_gender',
             ))
         ;
 
diff --git a/cookbook/form/create_form_type_extension.rst b/cookbook/form/create_form_type_extension.rst
index 153b0b7fc57..39e23350f80 100644
--- a/cookbook/form/create_form_type_extension.rst
+++ b/cookbook/form/create_form_type_extension.rst
@@ -312,7 +312,7 @@ next to the file field. For example::
 
         public function getName()
         {
-            return 'media';
+            return 'app_media';
         }
     }
 
diff --git a/cookbook/form/dynamic_form_modification.rst b/cookbook/form/dynamic_form_modification.rst
index 006955d9d67..7b5a5d589d2 100644
--- a/cookbook/form/dynamic_form_modification.rst
+++ b/cookbook/form/dynamic_form_modification.rst
@@ -246,7 +246,7 @@ Using an event listener, your form might look like this::
 
         public function getName()
         {
-            return 'friend_message';
+            return 'app_friend_message';
         }
 
         public function setDefaultOptions(OptionsResolverInterface $resolver)
@@ -393,7 +393,7 @@ it with :ref:`dic-tags-form-type`.
                 class: AppBundle\Form\Type\FriendMessageFormType
                 arguments: ['@security.context']
                 tags:
-                    - { name: form.type, alias: friend_message }
+                    - { name: form.type, alias: app_friend_message }
 
     .. code-block:: xml
 
@@ -401,7 +401,7 @@ it with :ref:`dic-tags-form-type`.
         <services>
             <service id="app.form.friend_message" class="AppBundle\Form\Type\FriendMessageFormType">
                 <argument type="service" id="security.context" />
-                <tag name="form.type" alias="friend_message" />
+                <tag name="form.type" alias="app_friend_message" />
             </service>
         </services>
 
@@ -409,7 +409,7 @@ it with :ref:`dic-tags-form-type`.
 
         // app/config/config.php
         $definition = new Definition('AppBundle\Form\Type\FriendMessageFormType');
-        $definition->addTag('form.type', array('alias' => 'friend_message'));
+        $definition->addTag('form.type', array('alias' => 'app_friend_message'));
         $container->setDefinition(
             'app.form.friend_message',
             $definition,
@@ -430,7 +430,7 @@ class, you can simply call::
     {
         public function newAction(Request $request)
         {
-            $form = $this->createForm('friend_message');
+            $form = $this->createForm('app_friend_message');
 
             // ...
         }
@@ -441,7 +441,7 @@ You can also easily embed the form type into another form::
     // inside some other "form type" class
     public function buildForm(FormBuilderInterface $builder, array $options)
     {
-        $builder->add('message', 'friend_message');
+        $builder->add('message', 'app_friend_message');
     }
 
 .. _cookbook-form-events-submitted-data: