You can set custom properties on Entity attributes, View Object
For example, assume you have a Dept Entity Object with an attribute Dname of type (domain) nameLength. The purpose of the nameLength domain is to limit the length of the department name to a string of less than 10 characters. If you want to allow departments with longer names, you can define a custom property on the Dname attribute to override the value of 10; for example, a string length of less than 15.
Custom property values set on View Object attributes override custom property values set on Entity Object attributes and Domains. Thus, you can design multiple levels of property inheritance. For example, a View Object can have an attribute Dname of type (domain) nameLength which will inherit the restriction on the length of the department name to a string of less than 10 characters. The View Object can be defined with a custom property to override the value of 10 provided by the nameLength domain; for example, a string length of less than 20. Note that the custom property on the Dname attribute in the View Object will also override the custom property value defined on the Dname attribute for the Dept Entity Object.