Weblog posts sender nick and name details

PREFIX sioc: <http://rdfs.org/sioc/ns#>
PREFIX sioct: <http://rdfs.org/sioc/types#>
PREFIX foaf: <http://xmlns.com/foaf/0.1/>
CONSTRUCT
{
  ?post foaf:maker ?maker .
  ?maker foaf:nick ?nick .
  ?maker foaf:name ?fname .
}
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 } .
  }