1.the ontology is representation artifact(a specification),distinct from the world it models.
2.the term "semiformal ontology" refers to a ontology which has a few bits of formality but is largely informal.
3.To conclude I would say that all practical ontologies are semiformal,and the "sweet spot" is an ontology hat specifies clearly how you can commit to it.Both the formal and informal parts should be designed to make it easy to play by the rules:the formal by automated tes