diff --git a/README.md b/README.md
index fc92940..2abd66b 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,13 @@
-| Variable                                                                                                                                                                  | Description                                             |
-|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------------------------------------------------|
-| **<a id="vps_domain_name" name="vps_domain_name">vps_domain_name</a>**<br/>[`string`](https://rougail.readthedocs.io/en/latest/variable.html#variables-types) `mandatory` | The domain name of the VPS.<br/>**Example**: example.fr |
+# Vps target server system variables
+
+> [!NOTE]
+> 
+> **Path**: vps
+
+| Variable                                                                                                                                                                  | Description                                                                                                                                                                                                                                                                                                                                                 |
+|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| **<a id="vps.domain_name" name="vps.domain_name">vps.domain_name</a>**<br/>[`string`](https://rougail.readthedocs.io/en/latest/variable.html#variables-types) `mandatory` | The domain name of the VPS.<br/>**Example**: example.fr                                                                                                                                                                                                                                                                                                     |
+| **<a id="vps.ssh_key" name="vps.ssh_key">vps.ssh_key</a>**<br/>[`UNIX filename`](https://rougail.readthedocs.io/en/latest/variable.html#variables-types)                  | Vps ssh private key.<br/>- The ssh key path must be accessible (the file must be present)<br/>- It is possible not to declare (if the ssh key is your default key).<br/>**Validators**: <br/>•&nbsp;this filename could be a relative path<br/>•&nbsp;this file must exist<br/>•&nbsp;file type allowed: "file"<br/>**Example**: ./sshkeys/myssh_privatekey |
 
 # Pedagogic html static file server
 
@@ -20,11 +27,15 @@
 > - Activation of the Nginx site: The site is enabled by creating a symbolic link in the sites-enabled directory.\
 > - Testing the Nginx configuration: The Nginx configuration is tested before restarting the service.\
 > - Restarting Nginx: Nginx is restarted to apply the changes.\
+> \
+> Dependencies:.\
+> \
+> - ubuntu 24.04 linux distribution.\
 > **Path**: nginx
 
 | Variable                                                                                                                                                                                     | Description                                                                                                                                                             |
 |----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
-| **<a id="nginx.domain_name" name="nginx.domain_name">nginx.domain_name</a>**<br/>[`domainname`](https://rougail.readthedocs.io/en/latest/variable.html#variables-types) `mandatory`          | Domain name.<br/>**Validator**: type domainname<br/>**Default**: the value of the variable "[The domain name of the VPS](#vps_domain_name)"<br/>**Example**: example.fr |
+| **<a id="nginx.domain_name" name="nginx.domain_name">nginx.domain_name</a>**<br/>[`domainname`](https://rougail.readthedocs.io/en/latest/variable.html#variables-types) `mandatory`          | Domain name.<br/>**Validator**: type domainname<br/>**Default**: the value of the variable "[The domain name of the VPS](#vps.domain_name)"<br/>**Example**: example.fr |
 | **<a id="nginx.email" name="nginx.email">nginx.email</a>**<br/>[`mail`](https://rougail.readthedocs.io/en/latest/variable.html#variables-types) `mandatory`                                  | Email for the domain name.<br/>This is for certbot.<br/>**Example**: contact@exemple.fr                                                                                 |
 | **<a id="nginx.htpasswd_file" name="nginx.htpasswd_file">nginx.htpasswd_file</a>**<br/>[`UNIX filename`](https://rougail.readthedocs.io/en/latest/variable.html#variables-types) `mandatory` | Htpassword user credential file name.<br/>**Validator**: file type allowed: "file"<br/>**Default**: /etc/nginx/.htpasswd                                                |