[out:xml][timeout:3600]; ( relation(9091108)['wikipedia'='de:Filstalbrücke (Neubaustrecke Wendlingen–Ulm)']; ); (._;>;); out meta qt;//['wikipedia tag links to 404']
[out:xml][timeout:3600]; ( node(105817850)['wikidata'='Q31949092']['wikipedia'='de:Deggingen']; node(105817852)['wikidata'='Q32386154']['wikipedia'='de:Bad Überkingen']; node(240082446)['wikidata'='Q49283971']['wikipedia'='de:Hattenhofen (Württemberg)']; node(34593177)['wikidata'='Q32750276']['wikipedia'='de:Süßen']; ); (._;>;); out meta qt;//['wikipedia wikidata mismatch']
[out:xml][timeout:3600]; ( node(12710462819)['information'='board']['wikipedia'='de:Burg Spitzenberg (Kuchen)']; ); (._;>;); out meta qt;//['information board with wikipedia tag, not subject:wikipedia']
[out:xml][timeout:3600]; ( relation(9255801)['network:wikidata'='Q15712258']['network:wikipedia'='en:Flixbus']; relation(9262564)['network:wikidata'='Q15712258']['network:wikipedia'='en:Flixbus']; relation(9691936)['network:wikidata'='Q15712258']['network:wikipedia'='en:Flixbus']; ); (._;>;); out meta qt;//['wikipedia wikidata mismatch - for network prefixed tags']
JOSM Wikipedia plugin
Note to self: online version hosted at https://matkoniecz.github.io/OSM-wikipedia-tag-validator-reports, files are stored at https://github.com/matkoniecz/OSM-wikipedia-tag-validator-reports.