Name a W3C Recommendation that starts with letter X
SELECT DISTINCT ?sbj ?sbj_label WHERE { ?sbj wdt:P31 wd:Q2661442 . ?sbj wdt:P1462 wd:Q37033 . ?sbj rdfs:label ?sbj_label . FILTER(STRSTARTS(lcase(?sbj_label), 'x')) . FILTER (lang(?sbj_label) = 'en') } LIMIT 25 
w3c recommendation: Q2661442 world wide web consortium: Q37033