Your main institution should be of type org:FormalOrganization and aiiso:Institution.
Sub-units should have org:subOrganizationOf and org:hasSubOrganization relationships with their containing unit.
If your institution is collegiate, then each college should be of type org:FormalOrganization and aiiso:College.
(TODO: Determine how to associate a college with a university to which it is affiliated.)
<rdf:RDF …> <aiiso:Institution rdf:about="#university-of-example"> <rdf:type rdf:resource="http://www.w3.org/ns/org#FormalOrganization"/> <rdfs:label>University of Example</rdfs:label> <org:hasSubOrganization> <aiiso:Division rdf:about="#humanities-division"> <rdfs:label>Humanities Division</rdfs:label> <org:subOrganizationOf rdf:resource="#university-of-example"/> </aiiso:Division> </org:hasSubOrganization> </aiiso:Institution> </rdf:RDF>