A link is an instance of an association and represents references between objects. It can be binary, in which case it is a path between two objects, or reflexive, in which case it involves a loop with each end attached to the same object. If the association name is shown, it is underlined to indicate an instance.
End names, aggregation, composition, navigability, and other adornments can be shown on the link ends or roles, but because links are instances, their ends do not show multiplicity. A link can also have a stereotype to indicate a particular kind of implementation.
Name a Link shape and add other property values
Open the element's UML Properties dialog box by double-clicking the icon that represents the element in the tree view or the shape that represents the element in a diagram.
Control which property values display on a shape in a diagram by right-clicking the shape, and then clicking Shape Display Options. In the UML Shape Display Options dialog box, select and clear options to display or hide property values.
Control which property values are displayed on the Link shape
Right-click the shape, click Shape Display Options, and then select or clear options to show or hide values.