Visual Dictionary
External Key Handling  
How to define an external key External keys need special handling when defining the dictionary. There are fundamentally two different type of External keys that can be handled by the Visual Dictionary system, those where the external key values can be found in the data record fields and those where the external key is independently derived.

If the External key consists of data that exists in the fields within the record, simply define the fields in the external key with the same name, size, and type. During the save sequence, the system will then recognize these fields and assign them accordingly.

If the External key consists of data that can not be found in the record, simply define the external key using unique field name and the system will define it as an independent field in the file.