diff --git a/conf/config.inc.php b/conf/config.inc.php
index 04b7177..e6710f0 100644
--- a/conf/config.inc.php
+++ b/conf/config.inc.php
@@ -197,6 +197,9 @@
 # Smarty debug mode - will popup debug information on web interface
 $smarty_debug = false;
 
+# The name of an HTTP Header that may hold a reference to an extra config file to include.
+#$header_name_extra_config="WP-Extra-Config";
+
 # Allow to override current settings with local configuration
 if (file_exists (dirname (__FILE__) . '/config.inc.local.php')) {
     include dirname (__FILE__) . '/config.inc.local.php';
@@ -207,4 +210,15 @@
     define("SMARTY", "/usr/share/php/smarty3/Smarty.class.php");
 }
 
+# Allow to override current settings with an extra configuration file, whose reference is passed in HTTP_HEADER $header_name_extra_config
+if (isset($header_name_extra_config)) {
+    $extraConfigKey = "HTTP_".strtoupper(str_replace('-','_',$header_name_extra_config));
+    if (array_key_exists($extraConfigKey, $_SERVER)) {
+        $extraConfig = preg_replace("/[^a-zA-Z0-9-_]+/", "", filter_var($_SERVER[$extraConfigKey], FILTER_SANITIZE_STRING, FILTER_FLAG_STRIP_HIGH));
+        if (strlen($extraConfig) > 0 && file_exists (__DIR__ . "/config.inc.".$extraConfig.".php")) {
+            require  __DIR__ . "/config.inc.".$extraConfig.".php";
+        }
+    }
+}
+
 ?>
diff --git a/docs/general-parameters.rst b/docs/general-parameters.rst
index f2f6fce..e65f5cb 100644
--- a/docs/general-parameters.rst
+++ b/docs/general-parameters.rst
@@ -19,6 +19,40 @@ White Pages default configuration file is ``white-pages/conf/config.inc.php``. I
   Do not copy ``config.inc.php`` into ``config.inc.local.php``, as the first one includes the second.
   You would then create an infinite loop and crash your application.
 
+Multi tenancy
+-------------
+
+You can load a specific configuration file by passing a HTTP header.
+This feature is disabled by default. To enable it:
+
+.. code-block:: php
+
+   $header_name_extra_config = "WP-Extra-Config";
+
+Then if you send the header ``WP-Extra-Config: domain1``, the file
+``conf/config.inc.domain1.php`` will be loaded.
+
+Using Apache, we may set such header using the following:
+
+.. code-block:: apache
+
+    <VirtualHost *:80>
+       ServerName wp.domain1.com
+       RequestHeader setIfEmpty WP-Extra-Config domain1
+       [...]
+    </VirtualHost>
+
+Using Nginx, we could use instead:
+
+.. code-block:: nginx
+
+   server {
+       [...]
+       location ~ \.php {
+           fastcgi_param WP-Extra-Config domain1;
+           [...]
+       }
+
 Language
 --------