Getting the UPC in an MWS response

Question

When using operation ListMatchingProducts or GetMatchingProductForId, is the UPC returned anywhere in the result?

If so, how do I access it?

If not, what service should I use to request it from Amazon? The Product Advertising API (formerly ECS)?

Answer 1

Somehow I completely missed this in the Product Advertising API docs!

For the response group Medium and Large, access UPC in the resulting object using:

$ecsResponse->Items->Item->ItemAttributes->UPC