## Creating an ontology

## Defining a namespace

A namespace is the topmost layer of an individual ontology, it will contain all classes and properties defined by it. In order to define a namespace you can do:

    # These prefixes will be used in the definition of the ontology,
    # thus must be explicitly defined
    @prefix nrl: <http://www.semanticdesktop.org/ontologies/2007/08/15/nrl#> .
    @prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
    @prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
    @prefix tracker: <http://www.tracker-project.org/ontologies/tracker#> .
    @prefix xsd: <http://www.w3.org/2001/XMLSchema#> .
    @prefix nao: <http://www.semanticdesktop.org/ontologies/2007/08/15/nao#> .

    # This is our example namespace
    @prefix ex: <http://example.org/#>

    ex: a tracker:Namespace, tracker:Ontology
        tracker:prefix "ex"
        rdfs:comment "example ontology"
        nao:lastModified "2017-01-01T15:00:00Z"