diff --git a/lib/Format.php b/lib/Format.php
index b7d50910..5f1324c5 100644
--- a/lib/Format.php
+++ b/lib/Format.php
@@ -1,51 +1,129 @@
 <?php
+/**
+ * This file is part of RSS-Bridge, a PHP project capable of generating RSS and
+ * Atom feeds for websites that don't have one.
+ *
+ * For the full license information, please view the UNLICENSE file distributed
+ * with this source code.
+ *
+ * @package	Core
+ * @license	http://unlicense.org/ UNLICENSE
+ * @link	https://github.com/rss-bridge/rss-bridge
+ */
 
+/**
+ * Factory class responsible for creating format objects from a given working
+ * directory.
+ *
+ * This class is capable of:
+ * - Locating format classes in the specified working directory (see {@see Format::$workingDir})
+ * - Creating new format instances based on the format's name (see {@see Format::create()})
+ *
+ * The following example illustrates the intended use for this class.
+ *
+ * ```PHP
+ * require_once __DIR__ . '/rssbridge.php';
+ *
+ * // Step 1: Set the working directory
+ * Format::setWorkingDir(__DIR__ . '/../formats/');
+ *
+ * // Step 2: Create a new instance of a format object (based on the name)
+ * $format = Format::create('Atom');
+ * ```
+ */
 class Format {
 
-	static protected $dirFormat;
+	/**
+	 * Holds a path to the working directory.
+	 *
+	 * Do not access this property directly!
+	 * Use {@see Format::setWorkingDir()} and {@see Format::getWorkingDir()} instead.
+	 *
+	 * @var string|null
+	 */
+	protected static $workingDir = null;
 
+	/**
+	 * Throws an exception when trying to create a new instance of this class.
+	 * Use {@see Format::create()} to create a new format object from the working
+	 * directory.
+	 *
+	 * @throws \LogicException if called.
+	 */
 	public function __construct(){
-		throw new \LogicException('Please use ' . __CLASS__ . '::create for new object.');
+		throw new \LogicException('Use ' . __CLASS__ . '::create($name) to create cache objects!');
 	}
 
-	public static function create($nameFormat){
-		if(!preg_match('@^[A-Z][a-zA-Z]*$@', $nameFormat)) {
-			throw new \InvalidArgumentException('Name format must be at least
- one uppercase follow or not by alphabetic characters.');
+	/**
+	 * Creates a new format object from the working directory.
+	 *
+	 * @throws \InvalidArgumentException if the requested format name is invalid.
+	 * @throws \Exception if the requested format file doesn't exist in the
+	 * working directory.
+	 * @param string $name Name of the format object.
+	 * @return object|bool The format object or false if the class is not instantiable.
+	 */
+	public static function create($name){
+		if(!preg_match('@^[A-Z][a-zA-Z]*$@', $name)) {
+			throw new \InvalidArgumentException('Format name invalid!');
 		}
 
-		$nameFormat = $nameFormat . 'Format';
-		$pathFormat = self::getDir() . $nameFormat . '.php';
+		$name = $name . 'Format';
+		$pathFormat = self::getWorkingDir() . $name . '.php';
 
 		if(!file_exists($pathFormat)) {
-			throw new \Exception('The format you are looking for does not exist.');
+			throw new \Exception('Format file ' . $filePath . ' does not exist!');
 		}
 
 		require_once $pathFormat;
 
-		return new $nameFormat();
+		if((new \ReflectionClass($name))->isInstantiable()) {
+			return new $name();
+		}
+
+		return false;
 	}
 
-	public static function setDir($dirFormat){
-		if(!is_string($dirFormat)) {
+	/**
+	 * Sets the working directory.
+	 *
+	 * @param string $dir Path to a directory containing cache classes
+	 * @throws \InvalidArgumentException if $dir is not a string.
+	 * @throws \Exception if the working directory doesn't exist.
+	 * @throws \InvalidArgumentException if $dir is not a directory.
+	 * @return void
+	 */
+	public static function setWorkingDir($dir){
+		self::$workingDir = null;
+
+		if(!is_string($dir)) {
 			throw new \InvalidArgumentException('Dir format must be a string.');
 		}
 
-		if(!file_exists($dirFormat)) {
-			throw new \Exception('Dir format does not exist.');
+		if(!file_exists($dir)) {
+			throw new \Exception('Working directory does not exist!');
 		}
 
-		self::$dirFormat = $dirFormat;
+		if(!is_dir($dir)) {
+			throw new \InvalidArgumentException('Working directory is not a directory!');
+		}
+
+		self::$workingDir = $dir;
 	}
 
-	public static function getDir(){
-		$dirFormat = self::$dirFormat;
-
-		if(is_null($dirFormat)) {
-			throw new \LogicException(__CLASS__ . ' class need to know format path !');
+	/**
+	 * Returns the working directory.
+	 * The working directory must be set with {@see Format::setWorkingDir()}!
+	 *
+	 * @throws \LogicException if the working directory is not set.
+	 * @return string The current working directory.
+	 */
+	public static function getWorkingDir(){
+		if(is_null(self::$workingDir)) {
+			throw new \LogicException('Working directory is not set!');
 		}
 
-		return $dirFormat;
+		return self::$workingDir;
 	}
 
 	/**
@@ -53,7 +131,7 @@ class Format {
 	* @return array Informations about each format
 	*/
 	public static function searchInformation(){
-		$pathDirFormat = self::getDir();
+		$pathDirFormat = self::getWorkingDir();
 
 		$listFormat = array();
 
diff --git a/lib/rssbridge.php b/lib/rssbridge.php
index 940913ee..74beb539 100644
--- a/lib/rssbridge.php
+++ b/lib/rssbridge.php
@@ -42,7 +42,7 @@ require_once PATH_LIB_VENDOR . 'php-urljoin/src/urljoin.php';
 // Initialize static members
 try {
 	Bridge::setWorkingDir(PATH_LIB_BRIDGES);
-	Format::setDir(PATH_LIB_FORMATS);
+	Format::setWorkingDir(PATH_LIB_FORMATS);
 	Cache::setWorkingDir(PATH_LIB_CACHES);
 } catch(Exception $e) {
 	error_log($e);