<https://help.smaregi.jp/hc/ja/articles/202518603--%E5%87%BA%E8%8D%B7-%E3%81%A7%E4%BB%95%E5%85%A5%E3%82%8C%E5%85%88%E3%81%AB%E5%95%86%E5%93%81%E3%82%92%E9%80%81%E3%82%8B-%E7%AE%A1%E7%90%86%E7%94%BB%E9%9D%A2->
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://help.smaregi.jp/hc/ja/articles/202518603>