Additional RSS namespaces

Here’s a (full?) list of RSS namespace extensions for podcasting, posted by Christopher Isene on the Podcast Index social network…

 'art19':              'https://art19.com/xmlns/rss-extensions/1.0',
  'atom':               'http://www.w3.org/2005/Atom',
  'atom10':             'http://www.w3.org/2005/Atom"',
  'cc':                 'http://web.resource.org/cc/',
  'content':            'http://purl.org/rss/1.0/modules/content/',
  'creativeCommons':    'http://backend.userland.com/creativeCommonsRssModule',
  'dc':                 'http://purl.org/dc/elements/1.1/',
  'ddn':                'http://discoverydn.com/about',
  'feedburner':         'http://rssnamespace.org/feedburner/ext/1.0',
  'feedpress':          'https://feed.press/xmlns',
  'geo':                'http://www.w3.org/2003/01/geo/wgs84_pos#',
  'georss':             'http://www.georss.org/georss',
  'googleplay':         'http://www.google.com/schemas/play-podcasts/1.0',
  'itunes':             'http://www.itunes.com/dtds/podcast-1.0.dtd',
  'media':              'http://search.yahoo.com/mrss/',
  'npr':                'https://www.npr.org/rss/',
  'nprml':              'https://api.npr.org/nprml',
  'rawvoice':           'http://www.rawvoice.com/rawvoiceRssModule/',
  'rdf':                'http://www.w3.org/1999/02/22-rdf-syntax-ns#',
  'slash':              'http://purl.org/rss/1.0/modules/slash/',
  'sr':                 'http://www.sverigesradio.se/podrss',
  'sy':                 'http://purl.org/rss/1.0/modules/syndication/',
  'wfw':                'http://wellformedweb.org/CommentAPI/',  

If you know any more, that would be great to add in the comments below.