def setup(app):
    app.add_crossref_type(
        directivename='setting',
        rolename='setting',
        indextemplate='pair: %s; setting',
    )
    app.add_crossref_type(
        directivename='templatetag',
        rolename='ttag',
        indextemplate='pair: %s; template tag',
    )
    app.add_crossref_type(
        directivename='templatefilter',
        rolename='tfilter',
        indextemplate='pair: %s; template filter',
    )
    app.add_crossref_type(
        directivename='fieldlookup',
        rolename='lookup',
        indextemplate='pair: %s; field lookup type',
    )