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+Introduction
+============
+
+# Configuration
+
+The module can provide configuration of system controllers. By convention,
+this configuration should be located in a separate file `controllers.config.php`
+in the configuration directory of module. This file must be included with the
+system configuration file:
+```
+project/
+    module/
+        ExampleModule/
+            Module.php
+            config/
+                system.config.php
+                controllers.config.php
+            src/
+            ...
+```
+
+The file `project/module/ExampleModule/config/system.config.php`:
+```
+return [
+    'controllers' => require __DIR__ . DIRECTORY_SEPARATOR . 'controllers.config.php',
+];
+```
+
+The file `project/module/ExampleModule/config/controllers.config.php`:
+```
+return [
+    'ExampleModule.Controller.Index' => 'ExampleModule\Controller\IndexController',
+    'ExampleModule.Controller.Bar' => 'ExampleModule\Controller\BarController',
+    // ...
+];
+``` 
+
+# Convention
+
+This should not be mandatory, to class of controller must be inherit any class.
+
+The files with controller classes should be located in the `Controller` directory.
+For directories is allowed any level of nesting:
+
+- `ExampleModule/src/Controller/IndexController`
+- `ExampleModule/src/Controller/Frontend/IndexController`
+- `ExampleModule/src/Frontend/Controller/IndexController`
+
+The controller classes must be ended with the `Controller` postfix:
+
+- `IndexController`
+- `FooController`
+- `BarController`
+
+The name of the controller action must be ended with the `Action` postfix:
+
+- `indexAction`
+- `fooAction`
+- `barAction`
+
+The action may accept as arguments:
+- As first argument - an instance of the `Psr\Http\Message\ServerRequestInterface`
+- As second argument - an instance of the `Psr\Http\Message\ResponseInterface`