def format_relation_name(value, format_type=None):
    """
    .. warning::

        The 'format_relation_name' function has been renamed 'format_resource_type' and the
        settings are now 'JSON_API_FORMAT_TYPES' and 'JSON_API_PLURALIZE_TYPES' instead of
        'JSON_API_FORMAT_RELATION_KEYS' and 'JSON_API_PLURALIZE_RELATION_TYPE'
    """
    warnings.warn(
        "The 'format_relation_name' function has been renamed 'format_resource_type' and the "
        "settings are now 'JSON_API_FORMAT_TYPES' and 'JSON_API_PLURALIZE_TYPES' instead of "
        "'JSON_API_FORMAT_RELATION_KEYS' and 'JSON_API_PLURALIZE_RELATION_TYPE'",
        DeprecationWarning
    )
    if format_type is None:
        format_type = json_api_settings.FORMAT_RELATION_KEYS
    pluralize = json_api_settings.PLURALIZE_RELATION_TYPE
    return format_resource_type(value, format_type, pluralize)
.. warning::

        The 'format_relation_name' function has been renamed 'format_resource_type' and the
        settings are now 'JSON_API_FORMAT_TYPES' and 'JSON_API_PLURALIZE_TYPES' instead of
        'JSON_API_FORMAT_RELATION_KEYS' and 'JSON_API_PLURALIZE_RELATION_TYPE'