def is_standalone(_item):
    """Definition of a standalone item

    :param _item: Zotero library item
    :type _item: dict
    :returns: True if standalone

    """
    # Zotero 6 write annotations in pdfs as a standalone item with parent being
    # the pdf file!

    return _item["data"]["itemType"] in ["note", "attachment", "annotation"] and \
        "parentItem" not in _item["data"]