<https://brtchip.com/faq/do-i-need-to-use-the-built-in-widgets-for-my-user-interface-design/#breadcrumb>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://brtchip.com/faq/do-i-need-to-use-the-built-in-widgets-for-my-user-interface-design/>