You can apply a business rule to a model object from the object's property sheet.
The business rules are added to the object and appear in the list of business rules for the object.
When you apply a business rule to an object, the U (Used) column beside this business rule is automatically checked in the List of business rules to indicate that the business rule is used by at least one object in the model. The U column allows you to visualize unused business rules, you can then delete them if necessary.