Corrected docs regarding RegisterLookupMixin subclasses.
@@ -36,7 +36,7 @@ Registration API
Django uses :class:`~lookups.RegisterLookupMixin` to give a class the interface to
register lookups on itself. The two prominent examples are
:class:`~django.db.models.Field`, the base class of all model fields, and
-``Aggregate``, the base class of all Django aggregates.
+:class:`Transform`, the base class of all Django transforms.
.. class:: lookups.RegisterLookupMixin
