BEcause more and more applications are SaaS application, it is harder and harder to make a select list from data from other applications or databases. This is because SaaS applications like finance application, protect access to their database directly. The only way to do this is via API calls. In this way the customer can control the API reguest and manipulate, alter, or adjust the return awnser that fills the select list.
This is a must have for Docuware to be able to integrate with other applications which databases are not reachable.