Updated docs

docs/guide/defining-documents.rst

@@ -344,6 +344,10 @@ Its value can take any of the following constants:
    their :file:`models.py` in the :const:`INSTALLED_APPS` tuple.
 
 
+.. warning::
+   Signals are not triggered when doing cascading updates / deletes - if this
+   is required you must manually handle the update / delete.
+
 Generic reference fields
 ''''''''''''''''''''''''
 A second kind of reference field also exists,

docs/guide/signals.rst

@@ -50,4 +50,11 @@ Example usage::
     signals.post_save.connect(Author.post_save, sender=Author)
 
 
+ReferenceFields and signals
+---------------------------
+
+Currently `reverse_delete_rules` do not trigger signals on the other part of
+the relationship.  If this is required you must manually handled the
+reverse deletion.
+
 .. _blinker: http://pypi.python.org/pypi/blinker

mongoengine/fields.py

@@ -709,6 +709,10 @@ class ReferenceField(BaseField):
 
         Bar.register_delete_rule(Foo, 'bar', NULLIFY)
 
+    .. note ::
+        `reverse_delete_rules` do not trigger pre / post delete signals to be
+        triggered.
+
     .. versionchanged:: 0.5 added `reverse_delete_rule`
     """