How to link with intersphinx to django-specific constructs (like settings)?

With a proper intersphinx setup, you can link to Django classes from your own documentation like this:

:class:`django:django.db.models.Model`

But how do you link to a setting? Django uses its own :setting: construct for that instead of something build-in like :class:. How do I link to a setting with intersphinx?

I've tried various incantations, but none work (and some are probably plain wrong):

:ref:`django:ROOT_URLCONF`
:ref:`django:root_urlconf`
:setting:`django:ROOT_URLCONF`
:ref:`django:setting:ROOT_URLCONF`
:django:setting:`ROOT_URLCONF`

Errors like undefined label: django:root_urlconf and Unknown interpreted text role "setting" greet me.