PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX svc: <http://rdfs.org/sioc/services#>
PREFIX sioct: <http://rdfs.org/sioc/types#>
SELECT *
WHERE
{
?forum a sioct:Weblog .
OPTIONAL { ?forum svc:has_service ?svc }.
OPTIONAL { ?svc svc:service_endpoint ?endp }.
OPTIONAL { ?svc svc:service_protocol ?proto }.
}