<https://tplfoundation.ca/atwood-letter/2312-tplf-seo-web-image-v2-3/#primaryimage>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://tplfoundation.ca/atwood-letter/2312-tplf-seo-web-image-v2-3/>