“…Our access control model is integrated with the models adopted in the Social Semantic Web. In particular, S4AC reuses concepts from SIOC 9 , SKOS 10 , WAC 11 , NiceTag 12 , SPIN 13 , Dublin Core 14 , and the access control model as a whole is grounded on further existing ontologies, such as FOAF 15 and RELATIONSHIP 16 . The main component of the S4AC model is the Access Policy, as presented in Definition 1.…”