query: #title: Check postal codes in Netherlands
  # Complex constraint from [[Property talk:P281]]
  #
  SELECT DISTINCT ?item ?zipCode 
  WHERE {
    ?item wdt:P17 wd:Q55; wdt:P281 ?zipCode. 
    FILTER(REGEX(STR(?zipCode), "^(\\d{4}(–\\d{4})?(\u00a0?[A-Z]+)?)$") = false)
  }
  ORDER BY ?item