<https://onlinecomputertips.com/keyword/folder-or-a-file-in-it-is-open-in-another-program/>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://onlinecomputertips.com/keyword/folder-or-a-file-in-it-is-open-in-another-program/>