Relationships between people.

Family relationships and relationships between people, are included in the information model in two main ways:

1. An ontology of relationships, using relationship types and person relation subclasses, the latter being aligned with the Snomed-CT 'Person' class.
2. The data model, whereby a related person is linked to another person via a relationship type and relation entity, the latter being aligned with the above

As with the common information model in general, the two are related to each other so an enquirer can build sophisticated relationship queries and advanced family trees.