diff --git a/README.md b/README.md
index 51197a4..1bef237 100644
--- a/README.md
+++ b/README.md
@@ -16,7 +16,7 @@ Rendered documents are produced in ODT format, and can then be converted to PDF,
 ## Rendering a Template
 
     from secreatary import Render
-    
+
     engine = Render(template)
     result = engine.render(foo=foo, bar=bar)
 
@@ -27,7 +27,7 @@ To render a template create an instance of class `Render` and call the instance'
 Before rendering a template, you can configure the internal templating engine using the `Render` instance's variable `environment`, which is an instance of jinja2 **[Environment][3]** class. For example, to declare a custom filter use:
 
     from secreatary import Render
-    
+
     engine = Render(template)
 
     # Configure custom application filters
@@ -54,9 +54,25 @@ Secretary will handle multiline variable values replacing the line breaks with a
 
 ### Control Flow
 
-To be documented... 
+To be documented...
+
+
+### Builtin Filters
+Apart of the available Jinja2 filters. Secretary includes some additionals filters. These are:
+
+- **markdown(value)**
+    Convert the value, a markdown formated string, into a ODT formated text. Example:
+
+        {{ invoice.description|markdown }}
+
+    **Output value will take the whole paragraph** so be aware of loosing text which is on the same paragraph of the markdown field.
+
+- **pad(value, length)**
+    Pad zeroes to `value` to the left until output's length will equal to `length`. Default output length is 5. Example:
+
+        {{ invoice.number|pad(6) }}
 
 
   [1]: http://jinja.pocoo.org/docs/templates/
   [2]: https://github.com/mirkonasato/pyodconverter
-  [3]: http://jinja.pocoo.org/docs/api/#jinja2.Environment
+  [3]: http://jinja.pocoo.org/docs/api/#jinja2.Environment
\ No newline at end of file
diff --git a/markdown_map.py b/markdown_map.py
index c09ce68..77b4d24 100644
--- a/markdown_map.py
+++ b/markdown_map.py
@@ -1,5 +1,7 @@
 #!/usr/bin/python
 
+from random import randint
+
 # Transform map used by the markdown filter. transform_map have
 # instructions of how to transform a HTML style tag into a ODT document
 # styled tag. Some ODT tags may need extra attributes; these are defined
@@ -39,7 +41,7 @@ common_styles = {
         }
     },
 
-    'p': { 
+    'p': {
         'replace_with': 'text:p',
         'style_attributes': {
             'style-name': 'Standard'
@@ -51,7 +53,8 @@ transform_map = {
 	'a': {
 		'replace_with': 'text:a',
 		'attributes': {
-			'xlink:type': 'simple'
+			'xlink:type': 'simple',
+			'xlink:href': ''
 		}
 	},
 
@@ -103,4 +106,22 @@ transform_map = {
             'style-name': 'Preformatted_20_Text'
         }
     },
+
+    'ul': {
+        'replace_with': 'text:list',
+        'attributes': {
+            'xml:id': 'list' + str(randint(100000000000000000,900000000000000000))
+        }
+    },
+
+    'ol': {
+        'replace_with': 'text:list',
+        'attributes': {
+            'xml:id': 'list' + str(randint(100000000000000000,900000000000000000))
+        }
+    },
+
+    'li': {
+        'replace_with': 'text:list-item'
+    },
 }
\ No newline at end of file
diff --git a/secretary.py b/secretary.py
index 860e026..209714d 100644
--- a/secretary.py
+++ b/secretary.py
@@ -38,7 +38,6 @@ import re
 import sys
 import zipfile
 import io
-from copy import deepcopy
 from xml.dom.minidom import parseString
 from jinja2 import Environment, Undefined
 
@@ -252,7 +251,7 @@ class Render(object):
 
                 keep_field = field
                 field_reference = field.getAttribute('text:description')
-                
+
                 if re.findall(r'\|markdown', field_content):
                     # a markdown should take the whole paragraph
                     field_reference = 'text:p'
@@ -295,10 +294,10 @@ class Render(object):
         """
 
         auto_styles = self.content.getElementsByTagName('office:automatic-styles')[0]
-        
+
         if not auto_styles.hasChildNodes():
             return None
-        
+
         for style_node in auto_styles.childNodes:
             if style_node.hasAttribute('style:name') and \
                (style_node.getAttribute('style:name') == style_name):
@@ -319,7 +318,7 @@ class Render(object):
         style_node.setAttribute('style:name', style_name)
         style_node.setAttribute('style:family', 'text')
         style_node.setAttribute('style:parent-style-name', 'Standard')
-        
+
         if attributes:
             for k, v in attributes.iteritems():
                 style_node.setAttribute('style:%s' % k, v)
@@ -337,6 +336,10 @@ class Render(object):
         """
             Convert a markdown text into a ODT formated text
         """
+
+        if not isinstance(markdown_text, basestring):
+            return ''
+
         from xml.dom import Node
         from markdown_map import transform_map
 
@@ -345,7 +348,7 @@ class Render(object):
         except ImportError:
             raise SecretaryError('Could not import markdown2 library. Install it using "pip install markdown2"')
 
-        styles_cache = {}   # cache styles searching     
+        styles_cache = {}   # cache styles searching
         html_text = markdown(markdown_text)
         xml_object = parseString('<html>%s</html>' % html_text)
 
@@ -394,12 +397,20 @@ class Render(object):
 
                 html_node.parentNode.replaceChild(odt_node, html_node)
 
+        def node_to_string(node):
+            result = node.toxml()
 
-        result = ''.join(c.toxml() for c in xml_object.getElementsByTagName('html')[0].childNodes)
-        # A double linebreak should be replacece with an empty paragraph
-        result = result.replace('\n\n', '<text:p text:style-name="Standard"/>')
-        return result
+            # linebreaks in preformated nodes should be converted to <text:line-break/>
+            if (node.__class__.__name__ != 'Text') and \
+                (node.getAttribute('text:style-name') == 'Preformatted_20_Text'):
+                result = result.replace('\n', '<text:line-break/>')
 
+            # All double linebreak should be replaced with an empty paragraph
+            return result.replace('\n\n', '<text:p text:style-name="Standard"/>')
+
+
+        return ''.join(node_as_str for node_as_str in map(node_to_string,
+                xml_object.getElementsByTagName('html')[0].childNodes))
 
 def render_template(template, **kwargs):
     """
diff --git a/setup.py b/setup.py
index f7fc066..8e7be1c 100644
--- a/setup.py
+++ b/setup.py
@@ -24,7 +24,7 @@ class PyTest(TestCommand):
 
 setup(
     name='secretary',
-    version='0.0.1',
+    version='0.1.0',
     url='https://github.com/christopher-ramirez/secretary',
     license='BSD',
     author='Christopher Ramírez',
@@ -32,7 +32,7 @@ setup(
     description=('Take the power of Jinja2 templates to OpenOffice and '
                  'LibreOffice and create reports and letters in your web applications'),
     long_description=read('README.md'),
-    py_modules=['secretary'],
+    py_modules=['secretary', 'markdown_map'],
     platforms='any',
     install_requires=[
         'Jinja2', 'markdown2'