Yes, that's what the projects have defined as the schema format. You can store other facts but they won't be displayed on the site. It also powers the search engine on the Dublin Core site . Uses modularized DTDs to represent rule communities. Some of the rules work like RDF triples.
More complex constructions can contain formalized rules.
It can all be converted to RDF 1.0 syntax. Jena Born of dissatisfaction with SiRPAC syntax. Can add properties to resources. Treats a statement as a resource but maintains difference between statement and reified statements. No, it treats them as literals.