diff --git a/README.md b/README.md
index c556780..8e8794d 100644
--- a/README.md
+++ b/README.md
@@ -1,9 +1,9 @@
 - [Summary](https://forge.cloud.silique.fr/stove/rougail-tutorials/src/branch/1.1/README.md)
-- [[tutorial 026] A variable with type "port"](https://forge.cloud.silique.fr/stove/rougail-tutorials/src/commit/v1.1_026/README.md) ([diff](https://forge.cloud.silique.fr/stove/rougail-tutorials/compare/v1.1_026~1..v1.1_026))
+- [[tutorial 027] A disabled family](https://forge.cloud.silique.fr/stove/rougail-tutorials/src/commit/v1.1_027/README.md) ([diff](https://forge.cloud.silique.fr/stove/rougail-tutorials/compare/v1.1_027~1..v1.1_027))
 
-# [tutorial 027] A disabled family
+# [tutorial 028] A conditional disabled family with a variable
 
-[View the diff](https://forge.cloud.silique.fr/stove/rougail-tutorials/compare/v1.1_027~1..v1.1_027)
+[View the diff](https://forge.cloud.silique.fr/stove/rougail-tutorials/compare/v1.1_028~1..v1.1_028)
 
 
 ## Screenshot
@@ -38,7 +38,10 @@ proxy_mode:
 ---
 manual:
   description: Manual proxy configuration
-  disabled: true
+  disabled:
+    type: variable
+    variable: proxy_mode
+    when_not: 'Manual proxy configuration'
 
   http_proxy:
     description: HTTP Proxy
@@ -62,9 +65,22 @@ foo@bar:~$ rougail -v 1.1 -m firefox/ -o doc -do github
 ```
 ### Variables
 
-| Variable&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;   | Description&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;   |
-|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
-| **proxy_mode**<br/>[`choice`](https://rougail.readthedocs.io/en/latest/variable.html#variables-types) `mandatory`                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  | Configure Proxy Access to the Internet.<br/>**Choices**: <br/>- No proxy ← (default)<br/>- Auto-detect proxy settings for this network<br/>- Use system proxy settings<br/>- Manual proxy configuration<br/>- Automatic proxy configuration URL                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
+| Variable&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;   | Description&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;   |
+|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| **proxy_mode**<br/>[`choice`](https://rougail.readthedocs.io/en/latest/variable.html#variables-types) `mandatory`                                                                                                                                                                                                                                                                                                                                                                                                                        | Configure Proxy Access to the Internet.<br/>**Choices**: <br/>- No proxy ← (default)<br/>- Auto-detect proxy settings for this network<br/>- Use system proxy settings<br/>- Manual proxy configuration<br/>- Automatic proxy configuration URL                                                                                                                                                                                                                                                                           |
+
+#### Manual proxy configuration
+
+_`disabled`_
+
+**Disabled**: proxy_mode.
+
+##### HTTP Proxy
+
+| Variable&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;   | Description&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;   |
+|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| **manual.http_proxy.address**<br/>[`domainname`](https://rougail.readthedocs.io/en/latest/variable.html#variables-types) `mandatory`                                                                                                                                                                                                                                                                                                                                                                                                     | HTTP address.<br/>**Validator**: the domain name can be an IP                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
+| **manual.http_proxy.port**<br/>[`port`](https://rougail.readthedocs.io/en/latest/variable.html#variables-types) `mandatory`                                                                                                                                                                                                                                                                                                                                                                                                              | HTTP Port.<br/>**Default**: 8080                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
 
 
 ## User data
@@ -121,26 +137,18 @@ proxy_mode: Manual proxy configuration
 ```console
 foo@bar:~$ rougail -v 1.1 -m firefox/ -u file -ff config/02/config.yaml
 ```
-<pre>╭────────────────────────── Caption ──────────────────────────╮
-│ Variable                           <span style="color: #ffd700">Default value</span>            │
-│ <span style="color: #5c5cff">Undocumented variable</span>              Modified value           │
-│ <span style="color: #ff0000">Undocumented but modified variable</span> (<span style="color: #00aa00">Original default value</span>) │
-╰─────────────────────────────────────────────────────────────╯
-Variables:
-<span style="color: #5c5cff">┗━━ </span>📓 proxy_mode: Manual proxy configuration (<span style="color: #00aa00">No proxy</span>)
+<pre>🛑 ERRORS
+<span style="color: #ff0000">┣━━ </span>The following variables are mandatory but have no value:
+<span style="color: #ff0000">┗━━ </span>  - manual.http_proxy.address (HTTP address)
 </pre>
 #### Output in read write mode
 
 ```console
 foo@bar:~$ rougail -v 1.1 -m firefox/ -u file -ff config/02/config.yaml --exporter.read_write
 ```
-<pre><pre>╭────────────────────────── Caption ──────────────────────────╮
-│ Variable                           <span style="color: #ffd700">Default value</span>            │
-│ <span style="color: #5c5cff">Undocumented variable</span>              Modified value           │
-│ <span style="color: #ff0000">Undocumented but modified variable</span> (<span style="color: #00aa00">Original default value</span>) │
-╰─────────────────────────────────────────────────────────────╯
-Variables:
-<span style="color: #5c5cff">┗━━ </span>📓 proxy_mode: Manual proxy configuration (<span style="color: #00aa00">No proxy</span>)
+<pre><pre>🛑 ERRORS
+<span style="color: #ff0000">┣━━ </span>The following variables are mandatory but have no value:
+<span style="color: #ff0000">┗━━ </span>  - manual.http_proxy.address (HTTP address)
 </pre>
 </pre>
 ### Example 3
@@ -161,15 +169,17 @@ manual:
 ```console
 foo@bar:~$ rougail -v 1.1 -m firefox/ -u file -ff config/03/config.yaml
 ```
-<pre>🛑 ERRORS
-<span style="color: #ff0000">┗━━ </span>cannot access to optiondescription "manual" (Manual proxy configuration) because has property "disabled"
-╭────────────────────────── Caption ──────────────────────────╮
+<pre>╭────────────────────────── Caption ──────────────────────────╮
 │ Variable                           <span style="color: #ffd700">Default value</span>            │
 │ <span style="color: #5c5cff">Undocumented variable</span>              Modified value           │
 │ <span style="color: #ff0000">Undocumented but modified variable</span> (<span style="color: #00aa00">Original default value</span>) │
 ╰─────────────────────────────────────────────────────────────╯
 Variables:
-<span style="color: #5c5cff">┗━━ </span>📓 proxy_mode: Manual proxy configuration (<span style="color: #00aa00">No proxy</span>)
+<span style="color: #5c5cff">┣━━ </span>📓 proxy_mode: Manual proxy configuration (<span style="color: #00aa00">No proxy</span>)
+<span style="color: #5c5cff">┗━━ </span>📂 manual
+<span style="color: #5c5cff">    </span><span style="color: #5c5cff">┗━━ </span>📂 http_proxy
+<span style="color: #5c5cff">    </span><span style="color: #5c5cff">    </span><span style="color: #5c5cff">┣━━ </span>📓 address: example.net
+<span style="color: #5c5cff">    </span><span style="color: #5c5cff">    </span><span style="color: #5c5cff">┗━━ </span>📓 port: <span style="color: #ffd700">8080</span>
 </pre>
 #### Output in read write mode
 
@@ -182,7 +192,11 @@ foo@bar:~$ rougail -v 1.1 -m firefox/ -u file -ff config/03/config.yaml --export
 │ <span style="color: #ff0000">Undocumented but modified variable</span> (<span style="color: #00aa00">Original default value</span>) │
 ╰─────────────────────────────────────────────────────────────╯
 Variables:
-<span style="color: #5c5cff">┗━━ </span>📓 proxy_mode: Manual proxy configuration (<span style="color: #00aa00">No proxy</span>)
+<span style="color: #5c5cff">┣━━ </span>📓 proxy_mode: Manual proxy configuration (<span style="color: #00aa00">No proxy</span>)
+<span style="color: #5c5cff">┗━━ </span>📂 manual
+<span style="color: #5c5cff">    </span><span style="color: #5c5cff">┗━━ </span>📂 http_proxy
+<span style="color: #5c5cff">    </span><span style="color: #5c5cff">    </span><span style="color: #5c5cff">┣━━ </span>📓 address: example.net
+<span style="color: #5c5cff">    </span><span style="color: #5c5cff">    </span><span style="color: #5c5cff">┗━━ </span>📓 port: <span style="color: #ffd700">8080</span>
 </pre>
 </pre>
 ### Example 4
@@ -204,16 +218,17 @@ manual:
 ```console
 foo@bar:~$ rougail -v 1.1 -m firefox/ -u file -ff config/04/config.yaml
 ```
-<pre>🛑 ERRORS
-<span style="color: #ff0000">┣━━ </span>cannot access to optiondescription "manual" (Manual proxy configuration) because has property "disabled"
-<span style="color: #ff0000">┗━━ </span>cannot access to optiondescription "manual" (Manual proxy configuration) because has property "disabled"
-╭────────────────────────── Caption ──────────────────────────╮
+<pre>╭────────────────────────── Caption ──────────────────────────╮
 │ Variable                           <span style="color: #ffd700">Default value</span>            │
 │ <span style="color: #5c5cff">Undocumented variable</span>              Modified value           │
 │ <span style="color: #ff0000">Undocumented but modified variable</span> (<span style="color: #00aa00">Original default value</span>) │
 ╰─────────────────────────────────────────────────────────────╯
 Variables:
-<span style="color: #5c5cff">┗━━ </span>📓 proxy_mode: Manual proxy configuration (<span style="color: #00aa00">No proxy</span>)
+<span style="color: #5c5cff">┣━━ </span>📓 proxy_mode: Manual proxy configuration (<span style="color: #00aa00">No proxy</span>)
+<span style="color: #5c5cff">┗━━ </span>📂 manual
+<span style="color: #5c5cff">    </span><span style="color: #5c5cff">┗━━ </span>📂 http_proxy
+<span style="color: #5c5cff">    </span><span style="color: #5c5cff">    </span><span style="color: #5c5cff">┣━━ </span>📓 address: example.net
+<span style="color: #5c5cff">    </span><span style="color: #5c5cff">    </span><span style="color: #5c5cff">┗━━ </span>📓 port: 3128 (<span style="color: #00aa00">8080</span>)
 </pre>
 #### Output in read write mode
 
@@ -226,7 +241,11 @@ foo@bar:~$ rougail -v 1.1 -m firefox/ -u file -ff config/04/config.yaml --export
 │ <span style="color: #ff0000">Undocumented but modified variable</span> (<span style="color: #00aa00">Original default value</span>) │
 ╰─────────────────────────────────────────────────────────────╯
 Variables:
-<span style="color: #5c5cff">┗━━ </span>📓 proxy_mode: Manual proxy configuration (<span style="color: #00aa00">No proxy</span>)
+<span style="color: #5c5cff">┣━━ </span>📓 proxy_mode: Manual proxy configuration (<span style="color: #00aa00">No proxy</span>)
+<span style="color: #5c5cff">┗━━ </span>📂 manual
+<span style="color: #5c5cff">    </span><span style="color: #5c5cff">┗━━ </span>📂 http_proxy
+<span style="color: #5c5cff">    </span><span style="color: #5c5cff">    </span><span style="color: #5c5cff">┣━━ </span>📓 address: example.net
+<span style="color: #5c5cff">    </span><span style="color: #5c5cff">    </span><span style="color: #5c5cff">┗━━ </span>📓 port: 3128 (<span style="color: #00aa00">8080</span>)
 </pre>
 </pre>
 ### Example 5
@@ -252,8 +271,6 @@ manual:
 foo@bar:~$ rougail -v 1.1 -m firefox/ -u file -ff config/05/config.yaml
 ```
 <pre>🛑 ERRORS
-<span style="color: #ff0000">┣━━ </span>cannot access to optiondescription "manual" (Manual proxy configuration) because has property "disabled"
-<span style="color: #ff0000">┣━━ </span>cannot access to optiondescription "manual" (Manual proxy configuration) because has property "disabled"
 <span style="color: #ff0000">┣━━ </span>unknown option "use_for_https" in optiondescription "manual" (Manual proxy configuration)
 <span style="color: #ff0000">┗━━ </span>unknown option "https_proxy" in optiondescription "manual" (Manual proxy configuration)
 ╭────────────────────────── Caption ──────────────────────────╮
@@ -262,7 +279,11 @@ foo@bar:~$ rougail -v 1.1 -m firefox/ -u file -ff config/05/config.yaml
 │ <span style="color: #ff0000">Undocumented but modified variable</span> (<span style="color: #00aa00">Original default value</span>) │
 ╰─────────────────────────────────────────────────────────────╯
 Variables:
-<span style="color: #5c5cff">┗━━ </span>📓 proxy_mode: Manual proxy configuration (<span style="color: #00aa00">No proxy</span>)
+<span style="color: #5c5cff">┣━━ </span>📓 proxy_mode: Manual proxy configuration (<span style="color: #00aa00">No proxy</span>)
+<span style="color: #5c5cff">┗━━ </span>📂 manual
+<span style="color: #5c5cff">    </span><span style="color: #5c5cff">┗━━ </span>📂 http_proxy
+<span style="color: #5c5cff">    </span><span style="color: #5c5cff">    </span><span style="color: #5c5cff">┣━━ </span>📓 address: http.proxy.net
+<span style="color: #5c5cff">    </span><span style="color: #5c5cff">    </span><span style="color: #5c5cff">┗━━ </span>📓 port: 3128 (<span style="color: #00aa00">8080</span>)
 </pre>
 #### Output in read write mode
 
@@ -275,9 +296,13 @@ foo@bar:~$ rougail -v 1.1 -m firefox/ -u file -ff config/05/config.yaml --export
 │ <span style="color: #ff0000">Undocumented but modified variable</span> (<span style="color: #00aa00">Original default value</span>) │
 ╰─────────────────────────────────────────────────────────────╯
 Variables:
-<span style="color: #5c5cff">┗━━ </span>📓 proxy_mode: Manual proxy configuration (<span style="color: #00aa00">No proxy</span>)
+<span style="color: #5c5cff">┣━━ </span>📓 proxy_mode: Manual proxy configuration (<span style="color: #00aa00">No proxy</span>)
+<span style="color: #5c5cff">┗━━ </span>📂 manual
+<span style="color: #5c5cff">    </span><span style="color: #5c5cff">┗━━ </span>📂 http_proxy
+<span style="color: #5c5cff">    </span><span style="color: #5c5cff">    </span><span style="color: #5c5cff">┣━━ </span>📓 address: http.proxy.net
+<span style="color: #5c5cff">    </span><span style="color: #5c5cff">    </span><span style="color: #5c5cff">┗━━ </span>📓 port: 3128 (<span style="color: #00aa00">8080</span>)
 </pre>
 </pre>
 
 
-- [[tutorial 028] A conditional disabled family with a variable](https://forge.cloud.silique.fr/stove/rougail-tutorials/src/commit/v1.1_028/README.md) ([diff](https://forge.cloud.silique.fr/stove/rougail-tutorials/compare/v1.1_028~1..v1.1_028))
+- [[tutorial 029] Type variable is optional](https://forge.cloud.silique.fr/stove/rougail-tutorials/src/commit/v1.1_029/README.md) ([diff](https://forge.cloud.silique.fr/stove/rougail-tutorials/compare/v1.1_029~1..v1.1_029))
diff --git a/config/02/output_ro.html b/config/02/output_ro.html
index 4c097ea..28450ac 100644
--- a/config/02/output_ro.html
+++ b/config/02/output_ro.html
@@ -1,8 +1,4 @@
-<pre>╭────────────────────────── Caption ──────────────────────────╮
-│ Variable                           <span style="color: #ffd700">Default value</span>            │
-│ <span style="color: #5c5cff">Undocumented variable</span>              Modified value           │
-│ <span style="color: #ff0000">Undocumented but modified variable</span> (<span style="color: #00aa00">Original default value</span>) │
-╰─────────────────────────────────────────────────────────────╯
-Variables:
-<span style="color: #5c5cff">┗━━ </span>📓 proxy_mode: Manual proxy configuration (<span style="color: #00aa00">No proxy</span>)
+<pre>🛑 ERRORS
+<span style="color: #ff0000">┣━━ </span>The following variables are mandatory but have no value:
+<span style="color: #ff0000">┗━━ </span>  - manual.http_proxy.address (HTTP address)
 </pre>
diff --git a/config/02/output_rw.html b/config/02/output_rw.html
index 4c097ea..28450ac 100644
--- a/config/02/output_rw.html
+++ b/config/02/output_rw.html
@@ -1,8 +1,4 @@
-<pre>╭────────────────────────── Caption ──────────────────────────╮
-│ Variable                           <span style="color: #ffd700">Default value</span>            │
-│ <span style="color: #5c5cff">Undocumented variable</span>              Modified value           │
-│ <span style="color: #ff0000">Undocumented but modified variable</span> (<span style="color: #00aa00">Original default value</span>) │
-╰─────────────────────────────────────────────────────────────╯
-Variables:
-<span style="color: #5c5cff">┗━━ </span>📓 proxy_mode: Manual proxy configuration (<span style="color: #00aa00">No proxy</span>)
+<pre>🛑 ERRORS
+<span style="color: #ff0000">┣━━ </span>The following variables are mandatory but have no value:
+<span style="color: #ff0000">┗━━ </span>  - manual.http_proxy.address (HTTP address)
 </pre>
diff --git a/config/03/output_ro.html b/config/03/output_ro.html
index 98e6cee..9a3ff4f 100644
--- a/config/03/output_ro.html
+++ b/config/03/output_ro.html
@@ -1,10 +1,12 @@
-<pre>🛑 ERRORS
-<span style="color: #ff0000">┗━━ </span>cannot access to optiondescription "manual" (Manual proxy configuration) because has property "disabled"
-╭────────────────────────── Caption ──────────────────────────╮
+<pre>╭────────────────────────── Caption ──────────────────────────╮
 │ Variable                           <span style="color: #ffd700">Default value</span>            │
 │ <span style="color: #5c5cff">Undocumented variable</span>              Modified value           │
 │ <span style="color: #ff0000">Undocumented but modified variable</span> (<span style="color: #00aa00">Original default value</span>) │
 ╰─────────────────────────────────────────────────────────────╯
 Variables:
-<span style="color: #5c5cff">┗━━ </span>📓 proxy_mode: Manual proxy configuration (<span style="color: #00aa00">No proxy</span>)
+<span style="color: #5c5cff">┣━━ </span>📓 proxy_mode: Manual proxy configuration (<span style="color: #00aa00">No proxy</span>)
+<span style="color: #5c5cff">┗━━ </span>📂 manual
+<span style="color: #5c5cff">    </span><span style="color: #5c5cff">┗━━ </span>📂 http_proxy
+<span style="color: #5c5cff">    </span><span style="color: #5c5cff">    </span><span style="color: #5c5cff">┣━━ </span>📓 address: example.net
+<span style="color: #5c5cff">    </span><span style="color: #5c5cff">    </span><span style="color: #5c5cff">┗━━ </span>📓 port: <span style="color: #ffd700">8080</span>
 </pre>
diff --git a/config/03/output_rw.html b/config/03/output_rw.html
index 4c097ea..9a3ff4f 100644
--- a/config/03/output_rw.html
+++ b/config/03/output_rw.html
@@ -4,5 +4,9 @@
 │ <span style="color: #ff0000">Undocumented but modified variable</span> (<span style="color: #00aa00">Original default value</span>) │
 ╰─────────────────────────────────────────────────────────────╯
 Variables:
-<span style="color: #5c5cff">┗━━ </span>📓 proxy_mode: Manual proxy configuration (<span style="color: #00aa00">No proxy</span>)
+<span style="color: #5c5cff">┣━━ </span>📓 proxy_mode: Manual proxy configuration (<span style="color: #00aa00">No proxy</span>)
+<span style="color: #5c5cff">┗━━ </span>📂 manual
+<span style="color: #5c5cff">    </span><span style="color: #5c5cff">┗━━ </span>📂 http_proxy
+<span style="color: #5c5cff">    </span><span style="color: #5c5cff">    </span><span style="color: #5c5cff">┣━━ </span>📓 address: example.net
+<span style="color: #5c5cff">    </span><span style="color: #5c5cff">    </span><span style="color: #5c5cff">┗━━ </span>📓 port: <span style="color: #ffd700">8080</span>
 </pre>
diff --git a/config/04/output_ro.html b/config/04/output_ro.html
index 57c06eb..56d3640 100644
--- a/config/04/output_ro.html
+++ b/config/04/output_ro.html
@@ -1,11 +1,12 @@
-<pre>🛑 ERRORS
-<span style="color: #ff0000">┣━━ </span>cannot access to optiondescription "manual" (Manual proxy configuration) because has property "disabled"
-<span style="color: #ff0000">┗━━ </span>cannot access to optiondescription "manual" (Manual proxy configuration) because has property "disabled"
-╭────────────────────────── Caption ──────────────────────────╮
+<pre>╭────────────────────────── Caption ──────────────────────────╮
 │ Variable                           <span style="color: #ffd700">Default value</span>            │
 │ <span style="color: #5c5cff">Undocumented variable</span>              Modified value           │
 │ <span style="color: #ff0000">Undocumented but modified variable</span> (<span style="color: #00aa00">Original default value</span>) │
 ╰─────────────────────────────────────────────────────────────╯
 Variables:
-<span style="color: #5c5cff">┗━━ </span>📓 proxy_mode: Manual proxy configuration (<span style="color: #00aa00">No proxy</span>)
+<span style="color: #5c5cff">┣━━ </span>📓 proxy_mode: Manual proxy configuration (<span style="color: #00aa00">No proxy</span>)
+<span style="color: #5c5cff">┗━━ </span>📂 manual
+<span style="color: #5c5cff">    </span><span style="color: #5c5cff">┗━━ </span>📂 http_proxy
+<span style="color: #5c5cff">    </span><span style="color: #5c5cff">    </span><span style="color: #5c5cff">┣━━ </span>📓 address: example.net
+<span style="color: #5c5cff">    </span><span style="color: #5c5cff">    </span><span style="color: #5c5cff">┗━━ </span>📓 port: 3128 (<span style="color: #00aa00">8080</span>)
 </pre>
diff --git a/config/04/output_rw.html b/config/04/output_rw.html
index 4c097ea..56d3640 100644
--- a/config/04/output_rw.html
+++ b/config/04/output_rw.html
@@ -4,5 +4,9 @@
 │ <span style="color: #ff0000">Undocumented but modified variable</span> (<span style="color: #00aa00">Original default value</span>) │
 ╰─────────────────────────────────────────────────────────────╯
 Variables:
-<span style="color: #5c5cff">┗━━ </span>📓 proxy_mode: Manual proxy configuration (<span style="color: #00aa00">No proxy</span>)
+<span style="color: #5c5cff">┣━━ </span>📓 proxy_mode: Manual proxy configuration (<span style="color: #00aa00">No proxy</span>)
+<span style="color: #5c5cff">┗━━ </span>📂 manual
+<span style="color: #5c5cff">    </span><span style="color: #5c5cff">┗━━ </span>📂 http_proxy
+<span style="color: #5c5cff">    </span><span style="color: #5c5cff">    </span><span style="color: #5c5cff">┣━━ </span>📓 address: example.net
+<span style="color: #5c5cff">    </span><span style="color: #5c5cff">    </span><span style="color: #5c5cff">┗━━ </span>📓 port: 3128 (<span style="color: #00aa00">8080</span>)
 </pre>
diff --git a/config/05/output_ro.html b/config/05/output_ro.html
index 0a2c978..984844a 100644
--- a/config/05/output_ro.html
+++ b/config/05/output_ro.html
@@ -1,6 +1,4 @@
 <pre>🛑 ERRORS
-<span style="color: #ff0000">┣━━ </span>cannot access to optiondescription "manual" (Manual proxy configuration) because has property "disabled"
-<span style="color: #ff0000">┣━━ </span>cannot access to optiondescription "manual" (Manual proxy configuration) because has property "disabled"
 <span style="color: #ff0000">┣━━ </span>unknown option "use_for_https" in optiondescription "manual" (Manual proxy configuration)
 <span style="color: #ff0000">┗━━ </span>unknown option "https_proxy" in optiondescription "manual" (Manual proxy configuration)
 ╭────────────────────────── Caption ──────────────────────────╮
@@ -9,5 +7,9 @@
 │ <span style="color: #ff0000">Undocumented but modified variable</span> (<span style="color: #00aa00">Original default value</span>) │
 ╰─────────────────────────────────────────────────────────────╯
 Variables:
-<span style="color: #5c5cff">┗━━ </span>📓 proxy_mode: Manual proxy configuration (<span style="color: #00aa00">No proxy</span>)
+<span style="color: #5c5cff">┣━━ </span>📓 proxy_mode: Manual proxy configuration (<span style="color: #00aa00">No proxy</span>)
+<span style="color: #5c5cff">┗━━ </span>📂 manual
+<span style="color: #5c5cff">    </span><span style="color: #5c5cff">┗━━ </span>📂 http_proxy
+<span style="color: #5c5cff">    </span><span style="color: #5c5cff">    </span><span style="color: #5c5cff">┣━━ </span>📓 address: http.proxy.net
+<span style="color: #5c5cff">    </span><span style="color: #5c5cff">    </span><span style="color: #5c5cff">┗━━ </span>📓 port: 3128 (<span style="color: #00aa00">8080</span>)
 </pre>
diff --git a/config/05/output_rw.html b/config/05/output_rw.html
index 4c097ea..ec2ef0c 100644
--- a/config/05/output_rw.html
+++ b/config/05/output_rw.html
@@ -4,5 +4,9 @@
 │ <span style="color: #ff0000">Undocumented but modified variable</span> (<span style="color: #00aa00">Original default value</span>) │
 ╰─────────────────────────────────────────────────────────────╯
 Variables:
-<span style="color: #5c5cff">┗━━ </span>📓 proxy_mode: Manual proxy configuration (<span style="color: #00aa00">No proxy</span>)
+<span style="color: #5c5cff">┣━━ </span>📓 proxy_mode: Manual proxy configuration (<span style="color: #00aa00">No proxy</span>)
+<span style="color: #5c5cff">┗━━ </span>📂 manual
+<span style="color: #5c5cff">    </span><span style="color: #5c5cff">┗━━ </span>📂 http_proxy
+<span style="color: #5c5cff">    </span><span style="color: #5c5cff">    </span><span style="color: #5c5cff">┣━━ </span>📓 address: http.proxy.net
+<span style="color: #5c5cff">    </span><span style="color: #5c5cff">    </span><span style="color: #5c5cff">┗━━ </span>📓 port: 3128 (<span style="color: #00aa00">8080</span>)
 </pre>