//Artefact:ModelClass/org/uml/stereotypes/associationends/Reference

An Attribute which is, from a data perspective, only referenced, not integrated. Typical, such references cross some "aggregate realm" boundary. For editing, this implies both instances are worked separately on (in the user interface as well as concerning database transactions. When im- or exported, the instances will typically be serialised as references, too, not constructed inplace.