Discussion Data Space PREFIX sioc: <http://rdfs.org/sioc/ns#> PREFIX sioct: <http://rdfs.org/sioc/types#> PREFIX foaf: <http://xmlns.com/foaf/0.1/> SELECT ?forum_name, ?post, ?mbox WHERE { ?forum a sioct:MessageBoard . ?forum sioc:id ?forum_name. ?forum sioc:container_of ?post. optional{ ?post foaf:maker ?maker }. optional{ ?maker foaf:mbox ?mbox } . } Sample Data (Live Query Results) Click Here for a live SPARQL Query (via SPARQL Protocol) against a collection of Discussion posts.