...
Field binding is used to create a field to input allow a value or response that is to be tied to an RPG program field. By using With field binding, a new field is created with the set name, data type, and length associated with the bound field when the rich display file is compiled. The newly created fields are then able to be used in your RPG program to have a value or response set from the program itself, or to receive a value or response from the application.
How to tell if If a field is able to be bound :The the field binding dialog button will be available in the property.:
Clicking this button will open the Field Binding Dialog:
...