Above and beyond attributes, operations, responsibilities, and constraints, you can add still more information to a class in the form of notes attached to the class.
You'll usually add a note to an attribute or operation. Figure 3.14 shows a note referring to a government standard that tells where to find out how serial numbers are generated for objects in the WashingMachine class.
Figure 3.14 An attached note provides further information about the class.
A note can contain a graphic as well as text.