    :attr:`~django.db.models.Options.index_together` options.
  
  Models
  ~~~~~~
  
  * The ``order_by`` argument of the
    :class:`~django.db.models.expressions.Window` expression now accepts string
    references to fields and transforms.
 
</s> remove             add_idx = [idx for idx in new_indexes if idx not in old_indexes]
            rem_idx = [idx for idx in old_indexes if idx not in new_indexes]
 </s> add             added_indexes = [idx for idx in new_indexes if idx not in old_indexes]
            removed_indexes = [idx for idx in old_indexes if idx not in new_indexes]
            renamed_indexes = []
            # Find renamed indexes.
            remove_from_added = []
            remove_from_removed = []
            for new_index in added_indexes:
                new_index_dec = new_index.deconstruct()
                new_index_name = new_index_dec[2].pop("name")
                for old_index in removed_indexes:
                    old_index_dec = old_index.deconstruct()
                    old_index_name = old_index_dec[2].pop("name")
                    # Indexes are the same except for the names.
                    if (
                        new_index_dec == old_index_dec
                        and new_index_name != old_index_name
                    ):
                        renamed_indexes.append((old_index_name, new_index_name, None))
                        remove_from_added.append(new_index)
                        remove_from_removed.append(old_index)
            # Remove renamed indexes from the lists of added and removed
            # indexes.
            added_indexes = [
                idx for idx in added_indexes if idx not in remove_from_added
            ]
            removed_indexes = [
                idx for idx in removed_indexes if idx not in remove_from_removed
            ] </s> remove                         "added_indexes": add_idx,
                        "removed_indexes": rem_idx,
 </s> add                         "added_indexes": added_indexes,
                        "removed_indexes": removed_indexes,
                        "renamed_indexes": renamed_indexes,
* The migrations autodetector now generates
  :class:`~django.db.migrations.operations.RenameIndex` operations instead of
  ``RemoveIndex`` and ``AddIndex``, when renaming indexes defined in the
  :attr:`Meta.indexes <django.db.models.Options.indexes>`.

    :attr:`~django.db.models.Options.index_together` options.
  
* The migrations autodetector now generates
  :class:`~django.db.migrations.operations.RenameIndex` operations instead of
  ``RemoveIndex`` and ``AddIndex``, when renaming indexes defined in the
  :attr:`Meta.indexes <django.db.models.Options.indexes>`.

  Models
  ~~~~~~
  
  * The ``order_by`` argument of the
    :class:`~django.db.models.expressions.Window` expression now accepts string
    references to fields and transforms.
keep add keep keep keep keep keep keep
 Refs #27064 -- Made migrations generate RenameIndex operations when renaming Meta.indexes. 
docs/releases/4.1.txt