diff --git a/source/development/bundles/custom-fields.rst b/source/development/bundles/custom-fields.rst
new file mode 100644
index 000000000..835921154
--- /dev/null
+++ b/source/development/bundles/custom-fields.rst
@@ -0,0 +1,119 @@
+.. Copyright (C)  2014 Champs Libres Cooperative SCRLFS
+   Permission is granted to copy, distribute and/or modify this document
+   under the terms of the GNU Free Documentation License, Version 1.3
+   or any later version published by the Free Software Foundation;
+   with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts.
+   A copy of the license is included in the section entitled "GNU
+   Free Documentation License".
+   
+Custom fields bundle
+====================
+
+This bundle provide the ability to add custom fields to existing entities.
+
+Those custom fields contains extra data and will be stored in the DB, along with other data's entities. It may be string, text, date, ... or a link to an existing or to-be-created other entities.
+
+In the database, custom fields are stored in json format.
+
+.. seealso::
+
+   The full specification discussed `here. <https://redmine.champs-libres.coop/issues/239>`_
+   
+   `JSON Type on postgresql documentation <http://www.postgresql.org/docs/9.3/static/datatype-json.html>`_
+   
+Custom Fields concepts
+----------------------
+
+.. warning::
+
+   This section is incomplete
+   
+Allow custom fields on a entity
+--------------------------------
+
+As a developer, you may allow your users to add custom fields on your entities.
+
+Create a json field on your entity
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Declare a json field in your database :
+
+.. code-block:: yaml
+
+   Chill\CustomFieldsBundle\Entity\BlopEntity:
+      type: entity
+      # ...
+      fields:
+         customField:
+            type: json_array
+            
+Create the field accordingly :
+
+.. code-block:: php
+
+   namespace Chill\CustomFieldsBundle\Entity;
+   
+   /**
+   * BlopEntity
+   */
+   class BlopEntity
+   {
+   
+   /**
+   * @var array
+   */
+   private $customField = array();
+   
+   /**
+   * This method will be required for the Form component to record the 
+   * custom fields into the class
+   *
+   * @param array $customField
+   * @return BlopEntity
+   */
+   public function setCustomField(array $customField)
+   {
+      $this->customField = $customField;
+      return $this;
+   }
+   
+   /**
+   * Required by Forms to retrieve informations
+   *
+   * @return array
+   */
+   public function getCustomField()
+   {
+      return $this->customField;
+   }
+            
+Declare your customizable class in configuration
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Two methods are available :
+
+* In your app/config.yml file. This is the easiest method, but discouraged because it will reduce the ease for installation.
+* In your Configuration class
+
+In app/config.yml file
+""""""""""""""""""""""
+
+Add those file under `chill_custom_fields` section :
+
+.. code-block:: yaml
+
+   chill_custom_fields:
+      customizables_class:
+         - { class: Chill\CustomFieldsBundle\Entity\BlopEntity, name: blop_entity }
+         
+* The `name` allow you to define a string which is translatable. This string will appears when chill's admin will add/retrieve new customFieldsGroup.
+* The class, which is a full FQDN class path
+
+
+
+
+.. glossary::
+
+   customFieldsGroup
+      TODO
+      
diff --git a/source/development/bundles/index.rst b/source/development/bundles/index.rst
new file mode 100644
index 000000000..c077c1633
--- /dev/null
+++ b/source/development/bundles/index.rst
@@ -0,0 +1,16 @@
+.. Copyright (C)  2014 Champs Libres Cooperative SCRLFS
+   Permission is granted to copy, distribute and/or modify this document
+   under the terms of the GNU Free Documentation License, Version 1.3
+   or any later version published by the Free Software Foundation;
+   with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts.
+   A copy of the license is included in the section entitled "GNU
+   Free Documentation License".
+
+Official bundles documentation
+###############################
+
+.. toctree::
+    :maxdepth: 2
+
+    Main Bundle <main.rst>
+    Custom Fields <custom-fields.rst>
diff --git a/source/development/bundles/main.rst b/source/development/bundles/main.rst
new file mode 100644
index 000000000..254317691
--- /dev/null
+++ b/source/development/bundles/main.rst
@@ -0,0 +1,22 @@
+.. Copyright (C)  2014 Champs Libres Cooperative SCRLFS
+   Permission is granted to copy, distribute and/or modify this document
+   under the terms of the GNU Free Documentation License, Version 1.3
+   or any later version published by the Free Software Foundation;
+   with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts.
+   A copy of the license is included in the section entitled "GNU
+   Free Documentation License".
+   
+Main bundle
+###########
+
+This bundle is **required** for running Chill.
+
+This bundle provide :
+
+* Access control model (users, groups, and all concepts)
+* ...
+
+
+.. warning::
+
+   this section is incomplete.
diff --git a/source/development/index.rst b/source/development/index.rst
index db2afa25f..c06ca6db5 100644
--- a/source/development/index.rst
+++ b/source/development/index.rst
@@ -16,8 +16,9 @@ As Chill rely on the `symfony <http://symfony.com>`_ framework, reading the fram
 
     Install Chill for development <installation.rst>
     Instructions to create a new bundle <create-a-new-bundle.rst>
-    Bundles and tests <make-test-working.rst>
+    Testing <make-test-working.rst>
     manual/index.rst
+    Official bundle's documentation <bundles/index.rst>
 
 
 Help, I am lost !