[out:xml][timeout:3600]; ( relation(12189268)['wikipedia'='de:Bahnstrecke Simbach—Pocking']; relation(12189461)['wikipedia'='de:Bahnstrecke Tutting—Kößlarn']; ); (._;>;); out meta qt;//['wikipedia tag links to 404']
[out:xml][timeout:3600]; ( relation(10356283)['wikidata'='Q2497454']['wikipedia'='de:Unterer Inn']; relation(14996132)['wikidata'='Q41308060']['wikipedia'='cs:Zlatá stezka']; relation(1854406)['wikidata'='Q41308060']['wikipedia'='cs:Zlatá stezka']; ); (._;>;); out meta qt;//['wikipedia wikidata mismatch']
[out:xml][timeout:3600]; ( relation(5453132)['network:wikidata'='Q109474577']['network:wikipedia'='de:Verkehrsgemeinschaft Landkreis Passau']; relation(5838193)['network:wikidata'='Q109474577']['network:wikipedia'='de:Verkehrsgemeinschaft Landkreis Passau']; ); (._;>;); out meta qt;//['wikipedia wikidata mismatch - for network prefixed tags']
[out:xml][timeout:3600]; ( node(11063692635)['genus:wikidata'='Q45417383)']; node(11063692636)['genus:wikidata'='Q45417383)']; ); (._;>;); out meta qt;//['malformed secondary wikidata tag - for genus 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.