I’d like to emphasize the importance of CSV, not only at the very beginning. Not everyone can learn a programming language like proteus, and a well-designed CSV import/export feature is an easy way to communicate with the rest of the world.
In my little world, I think about creating shipment labels. Programming an API to the service provider is good, but will at least cost several 100€s… In my case, it would take decades to pay back, because I do not send several parcels every day. But the service provider offers a CSV import feature.