diff --git a/Command/Command.php b/Command/CommandInterface.php
similarity index 100%
rename from Command/Command.php
rename to Command/CommandInterface.php
diff --git a/Decorator/Decorator.php b/Decorator/Decorator.php
index 74d526d..88c1b84 100644
--- a/Decorator/Decorator.php
+++ b/Decorator/Decorator.php
@@ -16,24 +16,25 @@ namespace DesignPatterns\Decorator;
  */
 
 /**
- * the Deoorator MUST implement the Renderer contract, this is the key-feature
+ * the Deoorator MUST implement the RendererInterface contract, this is the key-feature
  * of this design pattern. If not, this is no longer a Decorator but just a dumb
  * wrapper.
  */
-abstract class Decorator implements Renderer
+abstract class Decorator implements RendererInterface
 {
-
-    protected $_wrapped;
+    /**
+     * @var RendererInterface
+     */
+    protected $wrapped;
 
     /**
      * You must type-hint the wrapped component :
      * It ensures you can call renderData() in the subclasses !
      * 
-     * @param Renderer $wrappable
+     * @param RendererInterface $wrappable
      */
-    public function __construct(Renderer $wrappable)
+    public function __construct(RendererInterface $wrappable)
     {
-        $this->_wrapped = $wrappable;
+        $this->wrapped = $wrappable;
     }
 }
-
diff --git a/Decorator/RenderInJson.php b/Decorator/RenderInJson.php
index 0c521bd..0edc7ea 100644
--- a/Decorator/RenderInJson.php
+++ b/Decorator/RenderInJson.php
@@ -2,13 +2,20 @@
 
 namespace DesignPatterns\Decorator;
 
+/**
+ * Class RenderInJson
+ */
 class RenderInJson extends Decorator
 {
-
+    /**
+     * render data as JSON
+     *
+     * @return mixed|string
+     */
     public function renderData()
     {
-        $output = $this->_wrapped->renderData();
+        $output = $this->wrapped->renderData();
+
         return json_encode($output);
     }
-
 }
diff --git a/Decorator/RenderInXml.php b/Decorator/RenderInXml.php
index 599c2f5..5967b98 100644
--- a/Decorator/RenderInXml.php
+++ b/Decorator/RenderInXml.php
@@ -2,19 +2,28 @@
 
 namespace DesignPatterns\Decorator;
 
+/**
+ * Class RenderInXml
+ */
 class RenderInXml extends Decorator
 {
-
+    /**
+     * render data as XML
+     *
+     * @return mixed|string
+     */
     public function renderData()
     {
-        $output = $this->_wrapped->renderData();
-        // do some fany conversion to xml from array ...
+        $output = $this->wrapped->renderData();
+
+        // do some fancy conversion to xml from array ...
+
         $doc = new \DOMDocument();
+
         foreach ($output as $key => $val) {
             $doc->appendChild($doc->createElement('foo', 'bar'));
         }
 
         return $doc->saveXML();
     }
-
 }
diff --git a/Decorator/Renderer.php b/Decorator/Renderer.php
deleted file mode 100644
index af3c46b..0000000
--- a/Decorator/Renderer.php
+++ /dev/null
@@ -1,9 +0,0 @@
-<?php
-
-namespace DesignPatterns\Decorator;
-
-interface Renderer
-{
-
-    public function renderData();
-}
diff --git a/Decorator/RendererInterface.php b/Decorator/RendererInterface.php
new file mode 100644
index 0000000..f5f3e3f
--- /dev/null
+++ b/Decorator/RendererInterface.php
@@ -0,0 +1,16 @@
+<?php
+
+namespace DesignPatterns\Decorator;
+
+/**
+ * Class RendererInterface
+ */
+interface RendererInterface
+{
+    /**
+     * render data
+     *
+     * @return mixed
+     */
+    public function renderData();
+}
diff --git a/Decorator/Webservice.php b/Decorator/Webservice.php
index 1075341..a23f42c 100644
--- a/Decorator/Webservice.php
+++ b/Decorator/Webservice.php
@@ -2,19 +2,29 @@
 
 namespace DesignPatterns\Decorator;
 
-class Webservice implements Renderer
+/**
+ * Class Webservice
+ */
+class Webservice implements RendererInterface
 {
+    /**
+     * @var mixed
+     */
+    protected $data;
 
-    protected $_data;
-
+    /**
+     * @param mixed $data
+     */
     public function __construct($data)
     {
-        $this->_data = $data;
+        $this->data = $data;
     }
 
+    /**
+     * @return string
+     */
     public function renderData()
     {
-        return $this->_data;
+        return $this->data;
     }
-
 }
diff --git a/Tests/Decorator/DecoratorTest.php b/Tests/Decorator/DecoratorTest.php
index fce9e56..7f20bb6 100644
--- a/Tests/Decorator/DecoratorTest.php
+++ b/Tests/Decorator/DecoratorTest.php
@@ -42,7 +42,7 @@ class DecoratorTest extends \PHPUnit_Framework_TestCase
      */
     public function testDecoratorMustImplementsRenderer()
     {
-        $this->assertTrue(is_subclass_of('DesignPatterns\Decorator\Decorator', 'DesignPatterns\Decorator\Renderer'));
+        $this->assertTrue(is_subclass_of('DesignPatterns\Decorator\Decorator', 'DesignPatterns\Decorator\RendererInterface'));
     }
 
     /**
@@ -60,7 +60,7 @@ class DecoratorTest extends \PHPUnit_Framework_TestCase
      */
     public function testDecoratorOnlyAcceptRenderer()
     {
-        $mock = $this->getMock('DesignPatterns\Decorator\Renderer');
+        $mock = $this->getMock('DesignPatterns\Decorator\RendererInterface');
         $dec = $this->getMockForAbstractClass('DesignPatterns\Decorator\Decorator', array($mock));
         $this->assertNotNull($dec);
     }