Description of OIL
An ontology in OIL consists of two layers: meta-level and meta-meta-level.
The meta-meta-level or ontology container: describes features of such an ontology, like author, name, subject, etc. Dublin Core Metadata Set is used in this layer.
The meta-level or ontology definition: where the actual ontological definitions are provided. The main contribution of OIL is w.r.t this level.