<https://forum.ftrack.com/topic/1775-unassigning-an-artist-should-show-up-in-the-activities-tab/>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://forum.ftrack.com/topic/1775-unassigning-an-artist-should-show-up-in-the-activities-tab/>