Adding Products to a Sales Order

Adding Products to a Sales Order

In the API documentation is described how to insert SalesOrders with their products. I would like to add a product by using it's Product Name and not the Product Id. I believe the docs describe this being possible, but I can't get it working.

The documentation states:
1. A value for "Product Id" is mandatory. 
2.You can specify the product name if you do not have a valid product ID. 
I have tried various implementations. I have tried leaving the Product Id empty and filling in the Product Name. I have also tried to fill in the Product Name for the Product Id. I just can't get it working.

Since I am working on an application which does not know the product ids, but does know the names. And it would be a shame to have to make a request to the API if it possible to use the Product Name.

Does anyone have any idea how this should be implemented? Or have I completely misinterpreted the statement as described in the documentation?

Thanks!