Note there's a typo at the end here.  It'd be good to have a more concrete example too.  Perhaps something like...

    def get_filter_backends(self):
        if 'include_archived_items' in self.request.QUERY_PARAMS:
            # If `?include_achive_items` is appended to the URL, remove
            # the `FilterArchiveItems` class from our filter backend classes.
            return self.filter_backends.remove(FilterArchiveItems)
        return self.filter_backends