Invoices field "Invoice Templates": What is it for?

Just noticed the field “Invoice Templates” in the invoice module and have been playing around with it a bit.
It allows me to (multi-)select one or more pdf-templates for any given invoice record.

The only reason I can see for having this field would be that a project leader can define which PDF-template should be used per invoice record, when Administration prints out the PDF invoices and sends them to the respective debtors.

In my tests this field has no effect on the actions “Print PDF”, or any other similar action… unfortunately. When I hit “print as PDF” it still shows all available pdf-templates.

Can anyone shed some light on this? Is there any built-in functionality to define for each invoice record which pdf-templates to use? If not, how would one go about making this possible?