diff --git a/components/dotenv.rst b/components/dotenv.rst
index 77d8fa78462..6a7262ad446 100644
--- a/components/dotenv.rst
+++ b/components/dotenv.rst
@@ -67,6 +67,42 @@ The ``load()`` method never overwrites existing environment variables. Use the
 .. versionadded:: 4.2
     The ``Dotenv::overload()`` method was introduced in Symfony 4.2.
 
+Symfony follows and promotes the `app config recommendations`_ made by the
+Twelve-Factor App methodology. Among other things, it's recommended to not group
+env vars into environments (``dev``, ``prod``, ``test``, etc.)
+
+When deploying apps you should follow that recommendation strictly. However,
+when developing apps on your local machine, testing multiple apps in different
+environments with regular env vars is cumbersome. That's why Symfony provides a
+feature to define env vars per environment using the ``loadForEnv()`` method
+(but you should only use it on your local machine, not in production servers)::
+
+    // ...
+    $dotenv->loadForEnv('dev', __DIR__.'/.env');
+    // Looks for env vars in these files (and in this order):
+    //   .env.dev.local
+    //   .env.local
+    //   .env.dev
+    //   .env
+
+    // ...
+    $dotenv->loadForEnv('test', __DIR__.'/.env');
+    // In the 'test' environment, the '.env.local' file is ignored. This example
+    // looks for env vars in these files (and in this order):
+    //   .env.test.local
+    //   .env.test
+    //   .env
+
+The ``.env`` file should be committed to the shared repository and contains the
+default env var values for the app. The optional ``.env.local`` file shouldn't
+be committed to the repository and overrides the values of some env vars to run
+the app on your local machine. The other two optional files (``.env`` +
+"environment name" + ``.local`` and ``.env`` + "environment name") work
+similarly, but they are specific to some environment.
+
+.. versionadded:: 4.2
+    The ``Dotenv::loadForEnv()`` method was introduced in Symfony 4.2.
+
 You should never store a ``.env`` file in your code repository as it might
 contain sensitive information; create a ``.env.dist`` file with sensible
 defaults instead.
@@ -112,3 +148,4 @@ Embed commands via ``$()`` (not supported on Windows):
 
 .. _Packagist: https://packagist.org/packages/symfony/dotenv
 .. _twelve-factor applications: http://www.12factor.net/
+.. _`app config recommendations`: https://12factor.net/config