From cc9552e02855cc66f5541d5a76c2381b588edfd1 Mon Sep 17 00:00:00 2001
From: Daniel Siepmann <coding@daniel-siepmann.de>
Date: Thu, 16 Mar 2017 11:06:15 +0100
Subject: [PATCH] TASK: Document configuration option

Relates: #7
---
 Readme.rst | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/Readme.rst b/Readme.rst
index 1c3fb4c..ebb3c0a 100644
--- a/Readme.rst
+++ b/Readme.rst
@@ -82,3 +82,23 @@ What does it look like?
    ----------------------------------------------------------------------
 
    Time: 35ms; Memory: 5Mb
+
+Configuration
+=============
+
+Configuration is done through PHPCS Standards, e.g. provide a custom ``ruleset.xml`` or customize
+the provided one.
+
+``legacyExtensions``
+    Configures which extension names are legacy. Used to provide further checks and warnings about
+    possible legacy code. E.g. inside of non auto migrated situations.
+
+    Example:
+
+.. code:: xml
+
+  <rule ref="Typo3Update.LegacyClassnames.Instanceof">
+      <properties>
+          <property name="legacyExtensions" type="array" value="Extbase,Fluid,Frontend,Core"/>
+      </properties>
+  </rule>