Using Django admin template tags -

I want to use templatetags in contrib.admin in Djnago I am To do this, go to INSTALLED_APPS in settings.py.

  INSTALLED_APPS = ('django.contrib.auth', 'django.contrib.contenttypes',' Django.contrib.sessions', 'django.contrib.sites',' django.contrib. Messages', 'django.contrib.staticfiles',' django.contrib.admin ', ...)   
 but when I try to use a tag, it says Is  invalid block tag: 'x' . I tried to use the  'search_form'  and  'admin_list_filter'  tag and I saw an error for them. {% Admin_list_filter cl spec%} {% endfor%} for spec in  <% s {@}% {@}   
 What am I missing?  
 Thanks   
 
 
 The template tag is actually reusable by the Django administrator. To use  search_form  tags, you will need to provide a  ChangeList  example, which is coupled very tightly with Django Administrator.  
 To reuse tags you were able to do, you have to do tag libraries first. Therefore, you have to load the  admin_list  tag before using it in the  search_form  tag.  
  {% load_manager_list} {% search_form cl%}