Wikiword Tags PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> PREFIX sioc: <http://rdfs.org/sioc/ns#> PREFIX sioct: <http://rdfs.org/sioc/types#> PREFIX skos: <http://www.w3.org/2004/02/skos/core#> SELECT DISTINCT ?tag ?topic WHERE { ?forum a sioct:Wiki . ?forum sioc:container_of ?post. optional{ ?post sioc:topic ?topic . ?topic rdf:type skos:Concept . ?topic skos:prefLabel ?tag } } Sample Data (Live Query Results) Click Here for a live SPARQL Query (via SPARQL Protocol) against a Collection of Wikis tags.