diff --git a/README.md b/README.md
index dee69b85..a1e5fdc7 100644
--- a/README.md
+++ b/README.md
@@ -266,7 +266,7 @@ https://alice:cat@rss-bridge.org/bridge01/?action=display&bridge=FabriceBellardB
 
 ### How to create a new output format
 
-[Create a new format](https://rss-bridge.github.io/rss-bridge/Format_API/index.html).
+See `formats/PlaintextFormat.php` for an example.
 
 ### How to run unit tests and linter
 
diff --git a/actions/DisplayAction.php b/actions/DisplayAction.php
index 138319fe..8c9dd057 100644
--- a/actions/DisplayAction.php
+++ b/actions/DisplayAction.php
@@ -93,7 +93,7 @@ class DisplayAction implements ActionInterface
         return $response;
     }
 
-    private function createResponse(array $request, BridgeAbstract $bridge, FormatInterface $format)
+    private function createResponse(array $request, BridgeAbstract $bridge, FormatAbstract $format)
     {
         $items = [];
         $infos = [];
@@ -108,15 +108,15 @@ class DisplayAction implements ActionInterface
             if (isset($items[0]) && is_array($items[0])) {
                 $feedItems = [];
                 foreach ($items as $item) {
-                    $feedItems[] = new FeedItem($item);
+                    $feedItems[] = FeedItem::fromArray($item);
                 }
                 $items = $feedItems;
             }
             $infos = [
-                'name' => $bridge->getName(),
-                'uri'  => $bridge->getURI(),
-                'donationUri'  => $bridge->getDonationURI(),
-                'icon' => $bridge->getIcon()
+                'name'          => $bridge->getName(),
+                'uri'           => $bridge->getURI(),
+                'donationUri'   => $bridge->getDonationURI(),
+                'icon'          => $bridge->getIcon()
             ];
         } catch (\Exception $e) {
             if ($e instanceof HttpException) {
@@ -167,8 +167,8 @@ class DisplayAction implements ActionInterface
 
         // Create a unique identifier every 24 hours
         $uniqueIdentifier = urlencode((int)(time() / 86400));
-        $itemTitle = sprintf('Bridge returned error %s! (%s)', $e->getCode(), $uniqueIdentifier);
-        $item->setTitle($itemTitle);
+        $title = sprintf('Bridge returned error %s! (%s)', $e->getCode(), $uniqueIdentifier);
+        $item->setTitle($title);
         $item->setURI(get_current_url());
         $item->setTimestamp(time());
 
diff --git a/docs/08_Format_API/01_How_to_create_a_new_format.md b/docs/08_Format_API/01_How_to_create_a_new_format.md
deleted file mode 100644
index f031e65b..00000000
--- a/docs/08_Format_API/01_How_to_create_a_new_format.md
+++ /dev/null
@@ -1,24 +0,0 @@
-Create a new file in the `formats/` folder (see [Folder structure](../04_For_Developers/03_Folder_structure.md)).
-
-The file must be named according to following specification:
-
-* It starts with the type
-* The file name must end with 'Format'
-* The file type must be PHP, written in small letters (seriously!) ".php"
-
-**Examples:**
-
-Type | Filename
------|---------
-Atom | AtomFormat.php
-Html | HtmlFormat.php
-
-The file must start with the PHP tags and end with an empty line. The closing tag `?>` is [omitted](http://php.net/basic-syntax.instruction-separation).
-
-Example:
-
-```PHP
-<?PHP
-    // PHP code here
-// This line is empty (just imagine it!)
-```
\ No newline at end of file
diff --git a/docs/08_Format_API/02_FormatInterface.md b/docs/08_Format_API/02_FormatInterface.md
deleted file mode 100644
index 461990a7..00000000
--- a/docs/08_Format_API/02_FormatInterface.md
+++ /dev/null
@@ -1,132 +0,0 @@
-The `FormatInterface` interface defines functions that need to be implemented by all formats:
-
-* [display](#the-display-function)
-* [stringify](#the-stringify-function)
-* [setItems](#the-setitems-function)
-* [getItems](#the-getitems-function)
-* [setCharset](#the-setcharset-function)
-* [getCharset](#the-getcharset-function)
-* [setExtraInfos](#the-setextrainfos-function)
-* [getExtraInfos](#the-getextrainfos-function)
-* [getMimeType](#the-getmimetype-function)
-
-Find a [template](#template) at the end of this file
-
-# Functions
-
-## The `stringify` function
-
-The `stringify` function returns the items received by [`setItems`](#the-setitem-function) as string.
-
-```PHP
-stringify(): string
-```
-
-## The `setItems` function
-
-The `setItems` function receives an array of items generated by the bridge and must return the object instance. Each item represents an entry in the feed. For more information refer to the [collectData](../05_Bridge_API/02_BridgeAbstract.md#collectdata) function.
-
-```PHP
-setItems(array $items): self
-```
-
-## The `getItems` function
-
-The `getItems` function returns the items previously set by the [`setItems`](#the-setitems-function) function. If no items where set previously this function returns an error.
-
-```PHP
-getItems(): array
-```
-
-## The `setCharset` function
-
-The `setCharset` function receives the character set value as string and returns the object instance.
-
-```PHP
-setCharset(string): self
-```
-
-## The `getCharset` function
-
-The `getCharset` function returns the character set value.
-
-```PHP
-getCharset(): string
-```
-
-## The `setExtraInfos` function
-
-The `setExtraInfos` function receives an array of elements with additional information to generate format outputs and must return the object instance.
-
-```PHP
-setExtraInfos(array $infos): self
-```
-
-Currently supported information are:
-
-Name | Description
------|------------
-`name` | Defines the name as generated by the bridge
-`uri` | Defines the URI of the feed as generated by the bridge
-
-## The `getExtraInfos` function
-
-The `getExtraInfos` function returns the information previously set via the [`setExtraInfos`](#the-setextrainfos-function) function.
-
-```PHP
-getExtraInfos(): array
-```
-
-## The `getMimeType` function
-
-The `getMimeType` function returns the expected [MIME type](https://en.wikipedia.org/wiki/Media_type#Common_examples) of the format's output.
-
-```PHP
-parse_mime_type(): string
-```
-
-# Template
-
-This is a bare minimum template for a format:
-
-```PHP
-<?php
-class MyTypeFormat implements FormatInterface {
-    private $items;
-    private $charset;
-    private $extraInfos;
-
-    public function stringify(){
-        // Implement your code here
-        return ''; // Return items as string
-    }
-
-    public function setItems(array $items){
-        $this->items = $items;
-        return $this;
-    }
-
-    public function getItems(){
-        return $this->items;
-    }
-
-    public function setCharset($charset){
-        $this->charset = $charset;
-        return $this;
-    }
-
-    public function getCharset(){
-        return $this->charset;
-    }
-
-    public function setExtraInfos(array $infos){
-        $this->extraInfos = $infos;
-        return $this;
-    }
-
-    public function getExtraInfos(){
-        return $this->extraInfos;
-    }
-}
-// Imaginary empty line!
-```
diff --git a/docs/08_Format_API/index.md b/docs/08_Format_API/index.md
deleted file mode 100644
index c5b9e6af..00000000
--- a/docs/08_Format_API/index.md
+++ /dev/null
@@ -1,9 +0,0 @@
-A Format is a class that allows RSS-Bridge to turn items from a bridge into an RSS-feed format.
-It is developed in a PHP file located in the `formats/` folder
-[Folder structure](../04_For_Developers/03_Folder_structure.md)
-and either implements the
-[FormatInterface](../08_Format_API/02_FormatInterface.md)
-interface or extends the FormatAbstract class.
-
-For more information about how to create a new _Format_, read
-[How to create a new Format?](./01_How_to_create_a_new_format.md)
\ No newline at end of file
diff --git a/lib/ActionInterface.php b/lib/ActionInterface.php
index 4eb9cc65..220dfa50 100644
--- a/lib/ActionInterface.php
+++ b/lib/ActionInterface.php
@@ -1,28 +1,9 @@
 <?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
- */
-
-/**
- * Interface for action objects.
- */
 interface ActionInterface
 {
     /**
-     * Execute the action.
-     *
-     * Note: This function directly outputs data to the user.
-     *
-     * @return ?string
+     * @return string|Response
      */
     public function execute(array $request);
 }
diff --git a/lib/FeedItem.php b/lib/FeedItem.php
index 3d1b4509..4915c1b9 100644
--- a/lib/FeedItem.php
+++ b/lib/FeedItem.php
@@ -1,511 +1,30 @@
 <?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
- */
-
-/**
- * Represents a simple feed item for transformation into various feed formats.
- *
- * This class represents a feed item. A feed item is an entity that can be
- * transformed into various feed formats. It holds a set of pre-defined
- * properties:
- *
- * - **URI**: URI to the full article (i.e. "https://...")
- * - **Title**: The title
- * - **Timestamp**: A timestamp of when the item was first released
- * - **Author**: Name of the author
- * - **Content**: Body of the feed, as text or HTML
- * - **Enclosures**: A list of links to media objects (images, videos, etc...)
- * - **Categories**: A list of category names or tags to categorize the item
- *
- * _Note_: A feed item can have any number of additional parameters, all of which
- * may or may not be transformed to the selected output format.
- *
- * _Remarks_: This class supports legacy items via {@see FeedItem::__construct()}
- * (i.e. `$feedItem = \FeedItem($item);`). Support for legacy items may be removed
- * in future versions of RSS-Bridge.
- */
 class FeedItem
 {
-    /** @var string|null URI to the full article */
-    protected $uri = null;
+    protected ?string $uri = null;
+    protected ?string $title = null;
+    protected ?int $timestamp = null;
+    protected ?string $author = null;
+    protected ?string $content = null;
+    protected array $enclosures = [];
+    protected array $categories = [];
+    protected ?string $uid = null;
+    protected array $misc = [];
 
-    /** @var string|null Title of the item */
-    protected $title = null;
-
-    /** @var int|null Timestamp of when the item was first released */
-    protected $timestamp = null;
-
-    /** @var string|null Name of the author */
-    protected $author = null;
-
-    /** @var string|null Body of the feed */
-    protected $content = null;
-
-    /** @var array List of links to media objects */
-    protected $enclosures = [];
-
-    /** @var array List of category names or tags */
-    protected $categories = [];
-
-    /** @var string Unique ID for the current item */
-    protected $uid = null;
-
-    /** @var array Associative list of additional parameters */
-    protected $misc = []; // Custom parameters
-
-    /**
-     * Create object from legacy item.
-     *
-     * The provided array must be an associative array of key-value-pairs, where
-     * keys may correspond to any of the properties of this class.
-     *
-     * Example use:
-     *
-     * ```PHP
-     * <?php
-     * $item = array();
-     *
-     * $item['uri'] = 'https://www.github.com/rss-bridge/rss-bridge/';
-     * $item['title'] = 'Title';
-     * $item['timestamp'] = strtotime('now');
-     * $item['author'] = 'Unknown author';
-     * $item['content'] = 'Hello World!';
-     * $item['enclosures'] = array('https://github.com/favicon.ico');
-     * $item['categories'] = array('php', 'rss-bridge', 'awesome');
-     *
-     * $feedItem = new \FeedItem($item);
-     *
-     * ```
-     *
-     * The result of the code above is the same as the code below:
-     *
-     * ```PHP
-     * <?php
-     * $feedItem = \FeedItem();
-     *
-     * $feedItem->uri = 'https://www.github.com/rss-bridge/rss-bridge/';
-     * $feedItem->title = 'Title';
-     * $feedItem->timestamp = strtotime('now');
-     * $feedItem->autor = 'Unknown author';
-     * $feedItem->content = 'Hello World!';
-     * $feedItem->enclosures = array('https://github.com/favicon.ico');
-     * $feedItem->categories = array('php', 'rss-bridge', 'awesome');
-     * ```
-     *
-     * @param array $item (optional) A legacy item (empty: no legacy support).
-     * @return object A new object of this class
-     */
-    public function __construct($item = [])
+    public function __construct()
     {
-        if (!is_array($item)) {
-            Debug::log('Item must be an array!');
-        }
-
-        foreach ($item as $key => $value) {
-            $this->__set($key, $value);
+    }
+
+    public static function fromArray(array $itemArray): self
+    {
+        $item = new self();
+        foreach ($itemArray as $key => $value) {
+            $item->__set($key, $value);
         }
+        return $item;
     }
 
-    /**
-     * Get current URI.
-     *
-     * Use {@see FeedItem::setURI()} to set the URI.
-     *
-     * @return string|null The URI or null if it hasn't been set.
-     */
-    public function getURI()
-    {
-        return $this->uri;
-    }
-
-    /**
-     * Set URI to the full article.
-     *
-     * Use {@see FeedItem::getURI()} to get the URI.
-     *
-     * _Note_: Removes whitespace from the beginning and end of the URI.
-     *
-     * _Remarks_: Uses the attribute "href" or "src" if the provided URI is an
-     * object of simple_html_dom_node.
-     *
-     * @param object|string $uri URI to the full article.
-     * @return self
-     */
-    public function setURI($uri)
-    {
-        $this->uri = null; // Clear previous data
-
-        if ($uri instanceof simple_html_dom_node) {
-            if ($uri->hasAttribute('href')) { // Anchor
-                $uri = $uri->href;
-            } elseif ($uri->hasAttribute('src')) { // Image
-                $uri = $uri->src;
-            } else {
-                Debug::log('The item provided as URI is unknown!');
-            }
-        }
-        if (!is_string($uri)) {
-            Debug::log(sprintf('Expected $uri to be string but got %s', gettype($uri)));
-            return $this;
-        }
-        $uri = trim($uri);
-        // Intentionally doing a weak url validation here because FILTER_VALIDATE_URL is too strict
-        if (!preg_match('#^https?://#i', $uri)) {
-            Debug::log(sprintf('Not a valid url: "%s"', $uri));
-            return $this;
-        }
-        $this->uri = $uri;
-        return $this;
-    }
-
-    /**
-     * Get current title.
-     *
-     * Use {@see FeedItem::setTitle()} to set the title.
-     *
-     * @return string|null The current title or null if it hasn't been set.
-     */
-    public function getTitle()
-    {
-        return $this->title;
-    }
-
-    /**
-     * Set title.
-     *
-     * Use {@see FeedItem::getTitle()} to get the title.
-     *
-     * _Note_: Removes whitespace from beginning and end of the title.
-     *
-     * @param string $title The title
-     * @return self
-     */
-    public function setTitle($title)
-    {
-        $this->title = null; // Clear previous data
-
-        if (!is_string($title)) {
-            Debug::log('Title must be a string!');
-        } else {
-            $this->title = truncate(trim($title));
-        }
-
-        return $this;
-    }
-
-    /**
-     * Get current timestamp.
-     *
-     * Use {@see FeedItem::setTimestamp()} to set the timestamp.
-     *
-     * @return int|null The current timestamp or null if it hasn't been set.
-     */
-    public function getTimestamp()
-    {
-        return $this->timestamp;
-    }
-
-    /**
-     * Set timestamp of first release.
-     *
-     * _Note_: The timestamp should represent the number of seconds since
-     * January 1 1970 00:00:00 GMT (Unix time).
-     *
-     * _Remarks_: If the provided timestamp is a string (not numeric), this
-     * function automatically attempts to parse the string using
-     * [strtotime](http://php.net/manual/en/function.strtotime.php)
-     *
-     * @link http://php.net/manual/en/function.strtotime.php strtotime (PHP)
-     * @link https://en.wikipedia.org/wiki/Unix_time Unix time (Wikipedia)
-     *
-     * @param string|int $timestamp A timestamp of when the item was first released
-     * @return self
-     */
-    public function setTimestamp($timestamp)
-    {
-        $this->timestamp = null; // Clear previous data
-
-        if (
-            !is_numeric($timestamp)
-            && !$timestamp = strtotime($timestamp)
-        ) {
-            Debug::log('Unable to parse timestamp!');
-        }
-
-        if ($timestamp <= 0) {
-            Debug::log('Timestamp must be greater than zero!');
-        } else {
-            $this->timestamp = $timestamp;
-        }
-
-        return $this;
-    }
-
-    /**
-     * Get the current author name.
-     *
-     * Use {@see FeedItem::setAuthor()} to set the author.
-     *
-     * @return string|null The author or null if it hasn't been set.
-     */
-    public function getAuthor()
-    {
-        return $this->author;
-    }
-
-    /**
-     * Set the author name.
-     *
-     * Use {@see FeedItem::getAuthor()} to get the author.
-     *
-     * @param string $author The author name.
-     * @return self
-     */
-    public function setAuthor($author)
-    {
-        $this->author = null; // Clear previous data
-
-        if (!is_string($author)) {
-            Debug::log('Author must be a string!');
-        } else {
-            $this->author = $author;
-        }
-
-        return $this;
-    }
-
-    /**
-     * Get item content.
-     *
-     * Use {@see FeedItem::setContent()} to set the item content.
-     *
-     * @return string|null The item content or null if it hasn't been set.
-     */
-    public function getContent()
-    {
-        return $this->content;
-    }
-
-    /**
-     * Set item content.
-     *
-     * Note: This function casts objects of type simple_html_dom and
-     * simple_html_dom_node to string.
-     *
-     * Use {@see FeedItem::getContent()} to get the current item content.
-     *
-     * @param string|object $content The item content as text or simple_html_dom object.
-     * @return self
-     */
-    public function setContent($content)
-    {
-        $this->content = null; // Clear previous data
-
-        if (
-            $content instanceof simple_html_dom
-            || $content instanceof simple_html_dom_node
-        ) {
-            $content = (string)$content;
-        }
-
-        if (is_string($content)) {
-            $this->content = $content;
-        } else {
-            Debug::log(sprintf('Feed content must be a string but got %s', gettype($content)));
-        }
-
-        return $this;
-    }
-
-    /**
-     * Get item enclosures.
-     *
-     * Use {@see FeedItem::setEnclosures()} to set feed enclosures.
-     *
-     * @return array Enclosures as array of enclosure URIs.
-     */
-    public function getEnclosures()
-    {
-        return $this->enclosures;
-    }
-
-    /**
-     * Set item enclosures.
-     *
-     * Use {@see FeedItem::getEnclosures()} to get the current item enclosures.
-     *
-     * @param array $enclosures Array of enclosures, where each element links to
-     * one enclosure.
-     * @return self
-     */
-    public function setEnclosures($enclosures)
-    {
-        $this->enclosures = [];
-
-        if (is_array($enclosures)) {
-            foreach ($enclosures as $enclosure) {
-                if (
-                    !filter_var(
-                        $enclosure,
-                        FILTER_VALIDATE_URL,
-                        FILTER_FLAG_PATH_REQUIRED
-                    )
-                ) {
-                    Debug::log('Each enclosure must contain a scheme, host and path!');
-                } elseif (!in_array($enclosure, $this->enclosures)) {
-                    $this->enclosures[] = $enclosure;
-                }
-            }
-        } else {
-            Debug::log('Enclosures must be an array!');
-        }
-
-        return $this;
-    }
-
-    /**
-     * Get item categories.
-     *
-     * Use {@see FeedItem::setCategories()} to set item categories.
-     *
-     * @param array The item categories.
-     */
-    public function getCategories()
-    {
-        return $this->categories;
-    }
-
-    /**
-     * Set item categories.
-     *
-     * Use {@see FeedItem::getCategories()} to get the current item categories.
-     *
-     * @param array $categories Array of categories, where each element defines
-     * a single category name.
-     * @return self
-     */
-    public function setCategories($categories)
-    {
-        $this->categories = [];
-
-        if (is_array($categories)) {
-            foreach ($categories as $category) {
-                if (!is_string($category)) {
-                    Debug::log('Category must be a string!');
-                } else {
-                    $this->categories[] = $category;
-                }
-            }
-        } else {
-            Debug::log('Categories must be an array!');
-        }
-
-        return $this;
-    }
-
-    /**
-     * Get unique id
-     *
-     * Use {@see FeedItem::setUid()} to set the unique id.
-     *
-     * @param string The unique id.
-     */
-    public function getUid()
-    {
-        return $this->uid;
-    }
-
-    /**
-     * Set unique id.
-     *
-     * Use {@see FeedItem::getUid()} to get the unique id.
-     *
-     * @param string $uid A string that uniquely identifies the current item
-     * @return self
-     */
-    public function setUid($uid)
-    {
-        $this->uid = null; // Clear previous data
-
-        if (!is_string($uid)) {
-            Debug::log('Unique id must be a string!');
-        } elseif (preg_match('/^[a-f0-9]{40}$/', $uid)) {
-            // keep id if it already is a SHA-1 hash
-            $this->uid = $uid;
-        } else {
-            $this->uid = sha1($uid);
-        }
-
-        return $this;
-    }
-
-    /**
-     * Add miscellaneous elements to the item.
-     *
-     * @param string $key Name of the element.
-     * @param mixed $value Value of the element.
-     * @return self
-     */
-    public function addMisc($key, $value)
-    {
-        if (!is_string($key)) {
-            Debug::log('Key must be a string!');
-        } elseif (in_array($key, get_object_vars($this))) {
-            Debug::log('Key must be unique!');
-        } else {
-            $this->misc[$key] = $value;
-        }
-
-        return $this;
-    }
-
-    /**
-     * Transform current object to array
-     *
-     * @return array
-     */
-    public function toArray()
-    {
-        return array_merge(
-            [
-                'uri' => $this->uri,
-                'title' => $this->title,
-                'timestamp' => $this->timestamp,
-                'author' => $this->author,
-                'content' => $this->content,
-                'enclosures' => $this->enclosures,
-                'categories' => $this->categories,
-                'uid' => $this->uid,
-            ],
-            $this->misc
-        );
-    }
-
-    /**
-     * Set item property
-     *
-     * Allows simple assignment to parameters. This method is slower, but easier
-     * to implement in some cases:
-     *
-     * ```PHP
-     * $item = new \FeedItem();
-     * $item->content = 'Hello World!';
-     * $item->my_id = 42;
-     * ```
-     *
-     * @param string $name Property name
-     * @param mixed $value Property value
-     */
     public function __set($name, $value)
     {
         switch ($name) {
@@ -538,15 +57,6 @@ class FeedItem
         }
     }
 
-    /**
-     * Get item property
-     *
-     * Allows simple assignment to parameters. This method is slower, but easier
-     * to implement in some cases.
-     *
-     * @param string $name Property name
-     * @return mixed Property value
-     */
     public function __get($name)
     {
         switch ($name) {
@@ -573,4 +83,220 @@ class FeedItem
                 return null;
         }
     }
+
+    public function getURI(): ?string
+    {
+        return $this->uri;
+    }
+
+    /**
+     * Set URI to the full article.
+     *
+     * Use {@see FeedItem::getURI()} to get the URI.
+     *
+     * _Note_: Removes whitespace from the beginning and end of the URI.
+     *
+     * _Remarks_: Uses the attribute "href" or "src" if the provided URI is an
+     * object of simple_html_dom_node.
+     *
+     * @param simple_html_dom_node|object|string $uri URI to the full article.
+     */
+    public function setURI($uri)
+    {
+        $this->uri = null; // Clear previous data
+
+        if ($uri instanceof simple_html_dom_node) {
+            if ($uri->hasAttribute('href')) { // Anchor
+                $uri = $uri->href;
+            } elseif ($uri->hasAttribute('src')) { // Image
+                $uri = $uri->src;
+            } else {
+                Debug::log('The item provided as URI is unknown!');
+            }
+        }
+        if (!is_string($uri)) {
+            Debug::log(sprintf('Expected $uri to be string but got %s', gettype($uri)));
+            return;
+        }
+        $uri = trim($uri);
+        // Intentionally doing a weak url validation here because FILTER_VALIDATE_URL is too strict
+        if (!preg_match('#^https?://#i', $uri)) {
+            Debug::log(sprintf('Not a valid url: "%s"', $uri));
+            return;
+        }
+        $this->uri = $uri;
+    }
+
+    public function getTitle(): ?string
+    {
+        return $this->title;
+    }
+
+    public function setTitle($title)
+    {
+        $this->title = null;
+        if (!is_string($title)) {
+            Debug::log('Title must be a string!');
+        } else {
+            $this->title = truncate(trim($title));
+        }
+    }
+
+    public function getTimestamp(): ?int
+    {
+        return $this->timestamp;
+    }
+
+    public function setTimestamp($timestamp)
+    {
+        $this->timestamp = null;
+        if (
+            !is_numeric($timestamp)
+            && !$timestamp = strtotime($timestamp)
+        ) {
+            Debug::log('Unable to parse timestamp!');
+        }
+        if ($timestamp <= 0) {
+            Debug::log('Timestamp must be greater than zero!');
+        } else {
+            $this->timestamp = $timestamp;
+        }
+    }
+
+    public function getAuthor(): ?string
+    {
+        return $this->author;
+    }
+
+    public function setAuthor($author)
+    {
+        $this->author = null;
+        if (!is_string($author)) {
+            Debug::log('Author must be a string!');
+        } else {
+            $this->author = $author;
+        }
+        return $this;
+    }
+
+    public function getContent(): ?string
+    {
+        return $this->content;
+    }
+
+    /**
+     * @param string|object $content The item content as text or simple_html_dom object.
+     */
+    public function setContent($content)
+    {
+        $this->content = null;
+        if (
+            $content instanceof simple_html_dom
+            || $content instanceof simple_html_dom_node
+        ) {
+            $content = (string) $content;
+        }
+        if (is_string($content)) {
+            $this->content = $content;
+        } else {
+            Debug::log(sprintf('Feed content must be a string but got %s', gettype($content)));
+        }
+    }
+
+    public function getEnclosures(): array
+    {
+        return $this->enclosures;
+    }
+
+    public function setEnclosures($enclosures)
+    {
+        $this->enclosures = [];
+
+        if (!is_array($enclosures)) {
+            Debug::log('Enclosures must be an array!');
+            return;
+        }
+        foreach ($enclosures as $enclosure) {
+            if (
+                !filter_var(
+                    $enclosure,
+                    FILTER_VALIDATE_URL,
+                    FILTER_FLAG_PATH_REQUIRED
+                )
+            ) {
+                Debug::log('Each enclosure must contain a scheme, host and path!');
+            } elseif (!in_array($enclosure, $this->enclosures)) {
+                $this->enclosures[] = $enclosure;
+            }
+        }
+    }
+
+    public function getCategories(): array
+    {
+        return $this->categories;
+    }
+
+    public function setCategories($categories)
+    {
+        $this->categories = [];
+
+        if (!is_array($categories)) {
+            Debug::log('Categories must be an array!');
+            return;
+        }
+        foreach ($categories as $category) {
+            if (is_string($category)) {
+                $this->categories[] = $category;
+            } else {
+                Debug::log('Category must be a string!');
+            }
+        }
+    }
+
+    public function getUid(): ?string
+    {
+        return $this->uid;
+    }
+
+    public function setUid($uid)
+    {
+        $this->uid = null;
+        if (!is_string($uid)) {
+            Debug::log('Unique id must be a string!');
+        } elseif (preg_match('/^[a-f0-9]{40}$/', $uid)) {
+            // keep id if it already is SHA-1 hash
+            $this->uid = $uid;
+        } else {
+            $this->uid = sha1($uid);
+        }
+    }
+
+    public function addMisc($name, $value)
+    {
+        if (!is_string($name)) {
+            Debug::log('Key must be a string!');
+        } elseif (in_array($name, get_object_vars($this))) {
+            Debug::log('Key must be unique!');
+        } else {
+            $this->misc[$name] = $value;
+        }
+        return $this;
+    }
+
+    public function toArray(): array
+    {
+        return array_merge(
+            [
+                'uri' => $this->uri,
+                'title' => $this->title,
+                'timestamp' => $this->timestamp,
+                'author' => $this->author,
+                'content' => $this->content,
+                'enclosures' => $this->enclosures,
+                'categories' => $this->categories,
+                'uid' => $this->uid,
+            ],
+            $this->misc
+        );
+    }
 }
diff --git a/lib/FormatAbstract.php b/lib/FormatAbstract.php
index 3289d651..0304f627 100644
--- a/lib/FormatAbstract.php
+++ b/lib/FormatAbstract.php
@@ -1,132 +1,70 @@
 <?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 https://unlicense.org/ UNLICENSE
- * @link    https://github.com/rss-bridge/rss-bridge
- */
-
-/**
- * An abstract class for format implementations
- *
- * This class implements {@see FormatInterface}
- */
-abstract class FormatAbstract implements FormatInterface
+abstract class FormatAbstract
 {
-    /** The default charset (UTF-8) */
-    const DEFAULT_CHARSET = 'UTF-8';
-
-    /** MIME type of format output */
     const MIME_TYPE = 'text/plain';
 
-    /** @var string $charset The charset */
-    protected $charset;
+    protected string $charset = 'UTF-8';
+    protected array $items = [];
+    protected int $lastModified;
+    protected array $extraInfos = [];
 
-    /** @var array $items The items */
-    protected $items;
+    abstract public function stringify();
 
-    /**
-     * @var int $lastModified A timestamp to indicate the last modified time of
-     * the output data.
-     */
-    protected $lastModified;
-
-    /** @var array $extraInfos The extra infos */
-    protected $extraInfos;
-
-    /** {@inheritdoc} */
-    public function getMimeType()
+    public function getMimeType(): string
     {
         return static::MIME_TYPE;
     }
 
-    /**
-     * {@inheritdoc}
-     *
-     * @param string $charset {@inheritdoc}
-     */
-    public function setCharset($charset)
+    public function setCharset(string $charset)
     {
         $this->charset = $charset;
-
-        return $this;
     }
 
-    /** {@inheritdoc} */
-    public function getCharset()
+    public function getCharset(): string
     {
-        $charset = $this->charset;
-
-        if (is_null($charset)) {
-            return static::DEFAULT_CHARSET;
-        }
-        return $charset;
+        return $this->charset;
     }
 
-    /**
-     * Set the last modified time
-     *
-     * @param int $lastModified The last modified time
-     * @return void
-     */
-    public function setLastModified($lastModified)
+    public function setLastModified(int $lastModified)
     {
         $this->lastModified = $lastModified;
     }
 
-    /**
-     * {@inheritdoc}
-     *
-     * @param array $items {@inheritdoc}
-     */
     public function setItems(array $items)
     {
         $this->items = $items;
-
-        return $this;
-    }
-
-    /** {@inheritdoc} */
-    public function getItems()
-    {
-        if (!is_array($this->items)) {
-            throw new \LogicException(sprintf('Feed the %s with "setItems" method before !', get_class($this)));
-        }
-
-        return $this->items;
     }
 
     /**
-     * {@inheritdoc}
-     *
-     * @param array $extraInfos {@inheritdoc}
+     * @return FeedItem[] The items
      */
-    public function setExtraInfos(array $extraInfos = [])
+    public function getItems(): array
     {
-        foreach (['name', 'uri', 'icon', 'donationUri'] as $infoName) {
-            if (!isset($extraInfos[$infoName])) {
-                $extraInfos[$infoName] = '';
-            }
-        }
-
-        $this->extraInfos = $extraInfos;
-
-        return $this;
+        return $this->items;
     }
 
-    /** {@inheritdoc} */
-    public function getExtraInfos()
+    public function setExtraInfos(array $infos = [])
     {
-        if (is_null($this->extraInfos)) { // No extra info ?
-            $this->setExtraInfos(); // Define with default value
+        $extras = [
+            'name',
+            'uri',
+            'icon',
+            'donationUri',
+        ];
+        foreach ($extras as $extra) {
+            if (!isset($infos[$extra])) {
+                $infos[$extra] = '';
+            }
         }
+        $this->extraInfos = $infos;
+    }
 
+    public function getExtraInfos(): array
+    {
+        if (!$this->extraInfos) {
+            $this->setExtraInfos();
+        }
         return $this->extraInfos;
     }
 }
diff --git a/lib/FormatFactory.php b/lib/FormatFactory.php
index d27d7d6a..9cded40f 100644
--- a/lib/FormatFactory.php
+++ b/lib/FormatFactory.php
@@ -33,7 +33,7 @@ class FormatFactory
      * @throws \InvalidArgumentException
      * @param string $name The name of the format e.g. "Atom", "Mrss" or "Json"
      */
-    public function create(string $name): FormatInterface
+    public function create(string $name): FormatAbstract
     {
         if (! preg_match('/^[a-zA-Z0-9-]*$/', $name)) {
             throw new \InvalidArgumentException('Format name invalid!');
diff --git a/lib/FormatInterface.php b/lib/FormatInterface.php
deleted file mode 100644
index 49e36933..00000000
--- a/lib/FormatInterface.php
+++ /dev/null
@@ -1,77 +0,0 @@
-<?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
- */
-
-/**
- * The format interface
- *
- * @todo Add missing function to the interface
- * @todo Explain parameters and return values in more detail
- * @todo Return self more often (to allow call chaining)
- */
-interface FormatInterface
-{
-    /**
-     * Generate a string representation of the current data
-     *
-     * @return string The string representation
-     */
-    public function stringify();
-
-    public function setItems(array $items);
-
-    /**
-     * Return items
-     *
-     * @throws \LogicException if the items are not set
-     * @return FeedItem[] The items
-     */
-    public function getItems();
-
-    /**
-     * Set extra information
-     *
-     * @param array $infos Extra information
-     * @return self The format object
-     */
-    public function setExtraInfos(array $infos);
-
-    /**
-     * Return extra information
-     *
-     * @return array Extra information
-     */
-    public function getExtraInfos();
-
-    /**
-     * Return MIME type
-     *
-     * @return string The MIME type
-     */
-    public function getMimeType();
-
-    /**
-     * Set charset
-     *
-     * @param string $charset The charset
-     * @return self The format object
-     */
-    public function setCharset($charset);
-
-    /**
-     * Return current charset
-     *
-     * @return string The charset
-     */
-    public function getCharset();
-}
diff --git a/lib/bootstrap.php b/lib/bootstrap.php
index dc1c0f04..bc584541 100644
--- a/lib/bootstrap.php
+++ b/lib/bootstrap.php
@@ -12,20 +12,12 @@
  * @link    https://github.com/rss-bridge/rss-bridge
  */
 
-/** Path to the root folder of RSS-Bridge (where index.php is located) */
-const PATH_ROOT = __DIR__ . '/../';
-
-/** Path to the bridges library */
-
 /** Path to the formats library */
 const PATH_LIB_FORMATS = __DIR__ . '/../formats/';
 
 /** Path to the caches library */
 const PATH_LIB_CACHES = __DIR__ . '/../caches/';
 
-/** Path to the actions library */
-const PATH_LIB_ACTIONS = __DIR__ . '/../actions/';
-
 /** Path to the cache folder */
 const PATH_CACHE = __DIR__ . '/../cache/';
 
diff --git a/lib/logger.php b/lib/logger.php
index ed1f1179..5d95e673 100644
--- a/lib/logger.php
+++ b/lib/logger.php
@@ -148,6 +148,9 @@ final class StreamHandler
             $context
         );
         error_log($text);
+        if (Debug::isEnabled()) {
+            print sprintf("<pre>%s</pre>\n", e($text));
+        }
         //$bytes = file_put_contents('/tmp/rss-bridge.log', $text, FILE_APPEND | LOCK_EX);
     }
 }
diff --git a/tests/Formats/BaseFormatTest.php b/tests/Formats/BaseFormatTest.php
index 30ce1063..71e196f0 100644
--- a/tests/Formats/BaseFormatTest.php
+++ b/tests/Formats/BaseFormatTest.php
@@ -39,7 +39,7 @@ abstract class BaseFormatTest extends TestCase
 
             $items = [];
             foreach ($data['items'] as $item) {
-                $items[] = new \FeedItem($item);
+                $items[] = \FeedItem::fromArray($item);
             }
 
             return (object)[
diff --git a/tests/Formats/FormatImplementationTest.php b/tests/Formats/FormatImplementationTest.php
index 55c6335f..03ac6d51 100644
--- a/tests/Formats/FormatImplementationTest.php
+++ b/tests/Formats/FormatImplementationTest.php
@@ -24,7 +24,7 @@ class FormatImplementationTest extends TestCase
     public function testClassType($path)
     {
         $this->setFormat($path);
-        $this->assertInstanceOf(FormatInterface::class, $this->obj);
+        $this->assertInstanceOf(FormatAbstract::class, $this->obj);
     }
 
     public function dataFormatsProvider()