title: django admin colon syntax in template tags and in reverse function
body: <p>While learning with Django by Example, I have found something I don't yet know and haven't found any reference for it. I'm sure it is well documented somewhere, but I haven't found out how to search for it. Also, I apologize if I'm reasking an already answered question, I haven't found it here either. 
  What I would like to understand is the "admin: ..." syntax, which I met in several contexts:</p>
  
  <p>In a template .html file:</p>
  
  <pre><code>&lt;a href="{% url admin:todo_datetime_add %}"&gt;Add Todo items&lt;/a&gt;
  </code></pre>
  
  <p>In a view function:</p>
  
  <pre><code>return HttpResponseRedirect(reverse("admin:todo_item_changelist"))
  </code></pre>
  
  <p>I have gone through the djangoproject tutorial and the first 8 chapters of djangobook, and I didn't meet it there. I know, though, that in a reverse function a view function may be passed, and that {% %} template tags 'do something', but I have only seen dotted syntax used for these cases, so far. May it be that for referencing admin features, instead of the dotted syntax, we use this colon? 
  I would really appreciate some brief explanation on what it does, or a reference link would be great, too.
  And again, I'm sorry if I'm reasking an already answered question.</p>