📝 Add loop.parent explanations

Author: homersimpsons

doc/tags/for.rst

@@ -65,7 +65,7 @@ Variable              Description
 ``loop.first``        True if first iteration
 ``loop.last``         True if last iteration
 ``loop.length``       The number of items in the sequence
-``loop.parent``       The parent context
+``loop.parent``       The parent loop context, for example ``loop.parent.loop.index``
 ===================== =============================================================
 
 .. code-block:: twig
@@ -74,6 +74,12 @@ Variable              Description
         {{ loop.index }} - {{ user.username }}
     {% endfor %}
 
+    {% for user in users %}
+        {% for right in user.right %}
+            {{ loop.parent.loop.index }} - {{ user.username }} - {{ right }}
+        {% endfor %}
+    {% endfor %}
+
 .. note::
 
     The ``loop.length``, ``loop.revindex``, ``loop.revindex0``, and