In the frame of the European Big Data Value Data Week, 32 metadata experts from academia and industry attended the Workshop on Metadata Interoperability on 27 May 2021. The workshop was organised by Rigo Wenning, supported by the European H2020 projects MOSAICrOWN (Multi-Owner data Sharing for Analytics and Integration respecting Confidentiality and OWNer control) and TRAPEZE. See Report on Metadata Interoperability Workshop at the EBDV Data Week 2021. Piero Bonatti from Università di Napoli Federico II, gave a presentation entitled “Metadata, Policy and Reasoning” summarising the work carried out in the TRAPEZE project. The video was recorded and is available on youtube.