Bill for item purchased for a specific customer

I understand that I can track purchase of items bought specifically for a certain customer, so that when I invoice, I can bill for these items, and be assured that I have not forgotten to bill for any of these items.
I came across this once in the demo, but I have been unable to locate it again. Also, I have found little mention, and no tutorials on this important feature.
Any pointers appreciated

Chris

@chrisklinger I don’t think this feature exists out of the box. You can achieve this via custom fields though on your Purchase Order (Customer, Billed)

Thank you, rmehta. I will try this.

Your efforts, and the effort of all the coders and developer, is deeply appreciated.