...
This document provides the normative requirements for all IRIs created in the IOF for consistency and usability. An English language class and property naming scheme was selected after considering a numerical identity scheme to facilitate the use of the ontologies. The following sections define the rules for constructing the IRI and version IRI per OWL 2 specifications (reference below).
Protocol and Authority
All IOF IRIs must be resolvable and refer to a resource that can be retrieved from the internet. The form of the IRI must specify the protocol as either HTTP or HTTPS and the authority must be a domain administered and owned by the IOF or its parent organization. The authority can begin with an alternate to www depending on the name resolution requirements of the IOF and the routing of requests. For example, www.industrialontologies.org or onto.industrialontologies.org would be valid authorities. The IOF must choose a single authority for all ontologies released by the IOF.
...