This chapter focuses on the notion of importing terms from an ontology. Rather than proposing a specific formalism for this task and proving theorems about its properties, it starts by surveying a sample of lesser known papers on this topic in both the AI and Database literature. Based on this, it then derives a list of desirable properties for the notion of “
importing a set of identifiers from an exporting to an importing knowledge base
”, and provides a framework for alternate formal definitions of this notion. Some of the more novel aspects are the idea of modifying the exporting ontology before the subset of axioms to be imported is determined, and limiting the use of imported terms. The chapter concludes with a review of the concept of “expressive power”, and how it might apply to importing mechanisms.