Rating & Review Markups MUST be tied to specific items

First reported by Menashe Avramov, the Google Developers usage guidelines and policies page was updated for Reviews and Ratings. The following was added:

"Review and rating markup should be used to provide review and/or rating information about a specific item, not about a category or a list of items. For example, "hotels in Madrid", "summer dresses", or "cake recipes" are not specific items. See also our structured data policies for multiple entities on the same page."

The obvious take away here is that you're now required to assign your rating and review markups to a specific item. Please take the time to read over Googles Reviews and Ratings Resource to get an updated list of all the required code, as well as great code examples to work from.