One of the attributes of an object-oriented system is the inheritance of properties. While NAV is object based rather than object oriented, the properties that affect data validation are inherited. Properties such as decimal formatting are also inherited. If a property is explicitly defined in the table, it cannot be less restrictively defined elsewhere.

Controls that are bound to a table field will inherit the settings of the properties that are common to both the field definition and the control definition. This basic concept applies to inheritance of data properties, beginning from fields in tables to pages and reports, and then from pages and reports to controls within pages and reports. Inherited property settings that involve data validation cannot be overridden, but all others can be changed. This is another example of why it is generally best to define the properties in the table for consistency and ease of maintenance, rather than defining them for each instance of use in a page or a report.