PREFIX sioc: <http://rdfs.org/sioc/ns#> PREFIX sioct: <http://rdfs.org/sioc/types#> PREFIX foaf: <http://xmlns.com/foaf/0.1/> SELECT DISTINCT ?nick, ?fname, ?post WHERE { ?forum a sioct:Weblog . ?forum sioc:container_of ?post. optional{ ?post foaf:maker ?maker }. optional{ ?maker foaf:nick ?nick } . optional{ ?maker foaf:name ?fname } . }