Description Tatiana Fesenko 2008-09-05 09:18:00 EDT

Contraint as well as Properies are elements of utmost importance to model stereotypes. Now contraints are shown as labels in 'constraints' compartment of stereotype. However, one contraint can bound several elements. It cannot be displayed using current notation. 
Classic constraint notation, as a note symbol, allows to constrain several elements. We show constraint as a note on other UML2 Tools diagrams. 
Another approach is to show constraint as a dashed line between constrained element. UML spec allows it. However, I prefer the first solution, because it's more universal.

UML 2.1 spec, 7.3.10, says:
The constraint string may be placed in a note symbol and attached to each of the symbols for the constrained elements by
a dashed line. Figure 7.35 shows an example of a constraint in a note symbol.
If the constraint is shown as a dashed line between two elements, then an arrowhead may be placed on one end. The
direction of the arrow is relevant information within the constraint. The element at the tail of the arrow is mapped to the
first position and the element at the head of the arrow is mapped to the second position in the constrainedElements
collection.