The Association type reference set represents a set of unordered associations of a particular type between i.e. concepts, descriptions and relationships. The referencedComponentId references the source component of the association, whereas the reference set specific attribute, the targetComponentId, references the target component of the association.

Associations between components can be used to form groups of components, as illustrated in the diagram below. When using an association reference set to specify group, the sort order of the group members is not specified, as when using the Ordered type reference set.

Reference Set Specific Attributes