Just saw this article about Structured Data Penalty issues (Still trying to figure out why my website ranking has dropped so suddenly over the last month).
Spammy Structured Markup Penalty & Recovery – Use Schema Markup With Caution!
In looking at my site with Webmaster tools, I find that I have out of 417 items listed in the Structured Data group (I think it is because of lack of keywords on the rest of my items - adding them gradually), I have over 200 that are either missing required data or have what they are determining to by invalid data.
Example Image #1:
In this example, they are looking for the product name.
Example Image #2:
In this example, Google doesn't seem to like my "Identifier" label for what they are looking for as a label of "Product"...? Or is it the sku format they don't like?
Where (in the code I presume) and how do I change these values? Why are some ok and others not?