add missing last sentence

1 files changed, 8 insertions, 0 deletions

diff --git a/docs/narr/models.rst b/docs/narr/models.rst
index c726ae9b4..79286590a 100644
--- a/docs/narr/models.rst
+++ b/docs/narr/models.rst
@@ -266,6 +266,14 @@ subobjects should have a ``__name__`` attribute that matches the name by
 which they are retrieved from the container via ``__getitem__``. 
 This pattern continues recursively down the graph.
 
+The ``__parent__`` attributes of each node form a linked list
+that points "upward" toward the root. This is analogous to the 
+`..` entry in filesystem directories. If you follow the ``__parent__``
+values from any node in the traversal graph, you will eventually
+come to the root node, just like if you keep executing the
+``cd ..`` filesystem command, eventually you will reach the 
+filesystem root directory.
+
 .. warning:: If your root model object has a ``__name__`` argument
    that is not ``None`` or the empty string, URLs returned by the
    :func:`pyramid.url.model_url` function and paths generated by