def parse_non_lang_item_with_subkey(key: str, item: dict):
    """ Given a single item, in a list of XML values, which does not contain a language key,
        but does contain a hidden "sub label"
        e.g. {'$': 'geoscanid:123456'}
        create the key:value mapping for the associated column, adding the subkey to the column
        name
        e.g. key_geoscanid:123456
        :param key: the XML key associated with the list that this item came from
        :param item: the list item
        :returns: k, v - the key with which this item should be associated and the item's value
    """
    k, v = item['$'].split(':')

    if k not in ['geoscanid', 'info']:
        raise ValueError()

    k = f'{key}_{k}'
    return k, v