An n-ary link is an instance of an association and represents references between objects. An n-ary link is a path between n objects. 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 an N-ary 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 N-ary Link shape
Right-click the shape, click Shape Display Options, and then select or clear options to show or hide values.
Choose the number of n-ary link ends
Double-click the N-ary Link shape, and then, for LinkEnd Count, choose the number of ends you want.