fixup

Author: HeahDude

reference/constraints/Traverse.rst

@@ -20,7 +20,8 @@ Basic Usage
 In the following example, create three classes ``Book``, ``Author`` and
 ``Editor`` that all have constraints on their properties. Furthermore,
 ``Book`` stores an ``Author`` and an ``Editor`` instance that must be
-valid too::
+valid too. Instead of adding the ``Valid`` constraint to both fields,
+configure the ``Traverse`` constraint on the ``Book`` class.::
 
 .. configuration-block::