diff --git a/src/IDF/Template/Markdown.php b/src/IDF/Template/Markdown.php
index 8363014..6c09be4 100644
--- a/src/IDF/Template/Markdown.php
+++ b/src/IDF/Template/Markdown.php
@@ -36,19 +36,6 @@ class IDF_Template_Markdown extends Pluf_Template_Tag
     {
         $this->project = $request->project;
         $this->request = $request;
-        $filter = new IDF_Template_MarkdownPrefilter();
-        $text = $filter->go($text);
-        // The filter has replace < and > also in the code blocks so
-        // we need to revert them
-        $tmp = array();
-        foreach (preg_split("/\015\012|\015|\012/", $text, -1) as $s) {
-            if (0 === strpos($s, '    ')) {
-                $s = str_replace(array('&lt;', '&gt;'),
-                                 array('<', '>'), $s);
-            }
-            $tmp[] = $s;
-        }
-        $text = implode("\n", $tmp);
         // Replace like in the issue text
         $tag = new IDF_Template_IssueComment();
         $text = $tag->start($text, $request, false, false, false, false);
@@ -57,7 +44,8 @@ class IDF_Template_Markdown extends Pluf_Template_Tag
         $text = preg_replace_callback('#\[\[([A-Za-z0-9\-]+)\]\]#im',
                                       array($this, 'callbackWikiPage'), 
                                       $text);
-        echo Pluf_Text_MarkDown_parse($text);
+        $filter = new IDF_Template_MarkdownPrefilter();
+        echo $filter->go(Pluf_Text_MarkDown_parse($text));
     }
 
     function callbackWikiPage($m)
diff --git a/src/IDF/Template/MarkdownPrefilter.php b/src/IDF/Template/MarkdownPrefilter.php
index 5e56f82..4ca389d 100644
--- a/src/IDF/Template/MarkdownPrefilter.php
+++ b/src/IDF/Template/MarkdownPrefilter.php
@@ -1,34 +1,31 @@
 <?php
-/* -*- tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
-/*
-# ***** BEGIN LICENSE BLOCK *****
-# This file is part of InDefero, an open source project management application.
-# Copyright (C) 2008 Céondo Ltd and contributors.
-#
-# InDefero is free software; you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation; either version 2 of the License, or
-# (at your option) any later version.
-#
-# InDefero is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License
-# along with this program; if not, write to the Free Software
-# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
-#
-# ***** END LICENSE BLOCK ***** */
+  /* -*- tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+  /*
+   # ***** BEGIN LICENSE BLOCK *****
+   # This file is part of InDefero, an open source project management application.
+   # Copyright (C) 2008 Céondo Ltd and contributors.
+   #
+   # InDefero is free software; you can redistribute it and/or modify
+   # it under the terms of the GNU General Public License as published by
+   # the Free Software Foundation; either version 2 of the License, or
+   # (at your option) any later version.
+   #
+   # InDefero is distributed in the hope that it will be useful,
+   # but WITHOUT ANY WARRANTY; without even the implied warranty of
+   # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   # GNU General Public License for more details.
+   #
+   # You should have received a copy of the GNU General Public License
+   # along with this program; if not, write to the Free Software
+   # Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+   #
+   # ***** END LICENSE BLOCK ***** */
 
-/**
- * Strict class to only allow entities.
- */
+  /**
+   * Should be renamed MarkdownPostfilter.
+   */
 class IDF_Template_MarkdownPrefilter extends Pluf_Text_HTML_Filter
 {
-    public $allowed = array();
-    public $always_close = array();
-    public $remove_blanks = array();
     public $allowed_entities = array(
                                      'amp',
                                      'gt',
@@ -91,4 +88,81 @@ class IDF_Template_MarkdownPrefilter extends Pluf_Text_HTML_Filter
                                      'upsih', 
                                      'piv',
                                      );
+
+    public $allowed = array(
+                            'img' => array('src', 'class', 'alt', 'height', 'width'),
+                            'strong' => array(),
+                            'em' => array(),
+                            'b' => array(),
+                            'i' => array(),
+                            'ul' => array(),
+                            'ol' => array(),
+                            'li' => array(),
+                            'p' => array('align', 'class'),
+                            'div' => array('align', 'class'),
+                            'br' => array(),
+                            'pre' => array(),
+                            'table' => array('summary'),
+                            'caption' => array(),
+                            'tr' => array(),
+                            'td' => array('style'),
+                            'h1' => array(),
+                            'h2' => array(),
+                            'h3' => array(),
+                            'hr' => array(),
+                            'address' => array(),
+                            'a' => array('href', 'title', 'rel'),
+                            'blockquote' => array(),
+                            );
+    // tags which should always be self-closing (e.g. "<img />")
+    public $no_close = array(
+                             'img',
+                             'br',
+                             'hr',
+                             );
+
+    // tags which must always have seperate opening and closing tags
+    // (e.g. "<b></b>")
+    public $always_close = array(
+                                 'strong',
+                                 'em',
+                                 'b',
+                                 'i',
+                                 'ul',
+                                 'ol',
+                                 'li',
+                                 'p',
+                                 'table',
+                                 'caption',
+                                 'tr',
+                                 'td',
+                                 'span',
+                                 'a',
+                                 'blockquote',
+                                 'pre',
+                                 'iframe',
+                                 'h1', 'h2', 'h3', 'address'
+                                 );
+    // attributes which should be checked for valid protocols
+    public $protocol_attributes = array(
+                                        'src',
+                                        'href',
+                                        );
+    // protocols which are allowed
+    public $allowed_protocols = array(
+                                      'http',
+                                      'https',
+                                      'ftp',
+                                      'mailto',
+                                      );
+    // tags which should be removed if they contain no content
+    // (e.g. "<b></b>" or "<b />")
+    public $remove_blanks = array(
+                                  'p',
+                                  'strong',
+                                  'em',
+                                  'caption',
+                                  'li',
+                                  'span',
+                                  );
 }