A rule is a generic database object. One rule can be bound to many different tables. The Rules tab in the Properties page allows you to view the list of dependencies.
Unless all the dependencies are resolved, the rule cannot be dropped. You can see all the dependent objects by opening the property pages for them from dependencies tab. From the Properties page, you can unbind rules.
Displaying dependencies for a rule
Select the rule icon.
Select File | Dependencies.
In the Object Type box, select the object type you want to view. The options are tables and user-defined datatypes.
Click the Dependencies button on the General tab of the property sheet.
Right-click the rule icon. Select Dependencies from the shortcut menu.