All other keys are optional, but if present they will be interpreted
as described below. In all cases below where a 'configuring dict' is
mentioned, it will be checked for the special ``'()'`` key to see if a
-custom instantiation is required. If so, the mechanism described
-above is used to instantiate; otherwise, the context is used to
-determine how to instantiate.
+custom instantiation is required. If so, the mechanism described in
+:ref:`logging-config-dict-userdef` below is used to create an instance;
+otherwise, the context is used to determine what to instantiate.
* `formatters` - the corresponding value will be a dict in which each
key is a formatter id and each value is a dict describing how to