List of Collection attributes

   * content
   * description

PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX sioc: <http://rdfs.org/sioc/ns#>
SELECT distinct ?attribute
FROM <http://demo.openlinksw.com/Doc>
WHERE 
  {
    ?forum a sioc:Container .
    ?forum sioc:is_collection_of  ?collection.
    ?collection?attribute ?o  
   }
ORDER BY ?attribute

Sample Data (Live Query Results)

• Click *Here* for an Interactive-Web View of Virtuoso Documentation.
• Click *Here* for a live SPARQL Query (via SPARQL Protocol) against a list of Collection attributes.