A relation between information objects and any Entity (including information objects). It can be used to talk about e.g. entities are references of proper nouns: the proper noun 'Leonardo da Vinci' isAbout the Person Leonardo da Vinci; as well as to talk about sets of entities that can be described by a common noun: the common noun 'person' isAbout the set of all persons in a domain of discourse, which can be represented in DOLCE-Ultralite as an individual of the class: Collection .
The isReferenceOf relation is irreflexive, differently from its inverse isAbout.