diff --git a/docs/tutorial/calculation.rst b/docs/tutorial/calculation.rst
index 8c850addf..0c816c005 100644
--- a/docs/tutorial/calculation.rst
+++ b/docs/tutorial/calculation.rst
@@ -153,7 +153,6 @@ The default values can be calculated too.
 
 .. todo:: montrer aussi ici des exemples de calculs de valeurs variables, ce qui est un des usages principaux de jinja
 
-
 Using jinja in a dynamic family declaration
 -----------------------------------------------
 
@@ -173,10 +172,11 @@ the identifier's variable is named "identifier" by default. Sounds logical:
           - HTTPS
           - SOCKS
 
-
 Here the identifer's variable takes the value of the `dynamic` family parameter.
 
-We have another possibility:
+.. type-along:: Using a jinja calculation with a parameter
+
+We have the possibility to use a given variable variable inside a jinja calculation:
 
 .. extinclude:: https://forge.cloud.silique.fr/stove/rougail-tutorials/raw/tag/v1.1_050/firefox/20-manual.yml
    :language: yaml
@@ -225,7 +225,9 @@ We have another possibility:
             type: identifier
             when: 'HTTPS'
 
-Here in the `hidden` property we have the possibility to name an identifier:
+This can be done by defining a `my_identifier` variable.
+
+This jinja variable comes from the `params` parameter of the `hidden` property.
 
 .. code-block:: yaml
 
@@ -233,7 +235,8 @@ Here in the `hidden` property we have the possibility to name an identifier:
             my_identifier:
               type: identifier
 
-Here, the identifer is named `my_identifier`, in a jinja calculation: 
+Here the `hidden` property's value is defined by a jinja calculation. 
+In this jinja calculation we have a `my_identifier` jinja variable. 
 
 .. code-block:: yaml
 
@@ -248,11 +251,60 @@ Here, the identifer is named `my_identifier`, in a jinja calculation:
           description: |
             in HTTPS case if "manual.use_for_https" is set to True
 
+.. type-along:: The `when` and `when_not` parameter notation
+
+Handling the SOCKS version
+----------------------------
+
+Now we need to handle the SOKS version as show in the firefox configuration screenshot: 
+
+.. image:: images/firefox_soks_version.png
+
+
+We'll just add a choice variable with a default value and a disabled property: 
+
+.. code-block:: yaml
+
+    version:
+      description: SOCKS host version used by proxy
+      choices:
+        - v4
+        - v5
+      default: v5
+      disabled:
+        type: identifier
+        when: 'HTTPS'
+
+There is still something new about this YAML, though. It is the `when` parameter 
+of the `disabled` property. You have two possible notations: `when` or `when_not`. 
+These two notations are just a short hand of what we could express in jinja as 
+this code:
+
+.. code-block:: jinja
+
+    {% if identifier == 'HTTPS' %}
+    when the identifer equals 'HTTPS' then the SOCKS version is disabled 
+    {% endif %}
+   
+And the `when_not` parameter is just the logical opposite.
+
+Here is the final version of our YAML dynamic family:
+
+.. extinclude:: https://forge.cloud.silique.fr/stove/rougail-tutorials/raw/tag/v1.1_050/firefox/20-manual.yml
+   :language: yaml
+   :caption: firefox/20-proxy.yml
 
 
 .. keypoints:: Key points
 
+   **keywords**
+      
+   - calculation with a jinja type calculation
+   - calculation with a `when` or `when_not` parameter
+   - defining a jinja internal variable in a jinja calculation
+
+   **progress**
+
    Here we have come to the possibility of making any kind of calculations based on the state of the :term:`configuration`.
    This is an important feature to manage the stateful aspect of a configuration.
    
-   
diff --git a/docs/tutorial/images/firefox_soks_version.png b/docs/tutorial/images/firefox_soks_version.png
new file mode 100644
index 000000000..b7ca7aa08
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