@epistatacadam @alex that's the open streetmap standard layer. It's not that OSM doesn't have the data:
name Cardiff
name:ar كارديف
name:ceb Cardiff
name:cy Caerdydd
name:el Κάρντιφ
name:en Cardiff
name:fa کاردیف
name:pl Cardiff
name:sv Cardiff
name:uk Кардіфф
name:ur کارڈف
name:zh 卡迪夫

It's how the data is used to render the map.