  The semantic web has received many contributions of researchers as ontologies
which, in this context, i.e. within RDF linked data, are formalized
conceptualizations that might use different protocols, such as RDFS, OWL DL and
OWL FULL. In this article, we describe new expressive techniques which were
found necessary after elaborating dozens of OWL ontologies for the scientific
academy, the State and the civil society. They consist in: 1) stating possible
uses a property might have without incurring into axioms or restrictions; 2)
assigning a level of priority for an element (class, property, triple); 3)
correct depiction in diagrams of relations between classes, between individuals
which are imperative, and between individuals which are optional; 4) a
convenient association between OWL classes and SKOS concepts. We propose
specific rules to accomplish these enhancements and exemplify both its use and
the difficulties that arise because these techniques are currently not
established as standards to the ontology designer.
