query: #title: Commons sitelinks to be copied to P373 property
  # Complex constraint from [[Property talk:P373]]
  # Items with no P373, but with a category in the Commons sitelink. That category can be saved as P373.
  SELECT ?item ?sitelink WHERE {
    ?item ^schema:about [ schema:isPartOf <https://commons.wikimedia.org/>; schema:name ?sitelink ] . 
    MINUS { ?item wdt:P373 [] } .
    MINUS { ?item wdt:P31 wd:Q4167836 } .
    MINUS { ?item wdt:P31 wd:Q4167410 } .
    FILTER( STRSTARTS( ?sitelink, 'Category:' ) ) .
  } LIMIT 500