I've always been curious about posting a detailed description of some change we are merely considering in order to get advanced feedback on it (and, to ward of some of the "Why didn't you tell us!?!?!" in the case that we actually do implement it).
So, with that in mind, here's an internal design proposal document titled Food Freshness & Quality which I made over the weekend. It's unexpurgated (excepting removal of links to other documents or images that you wouldn't be able to get to) and it was written for an internal audience so some of the terminology might be weird.
To be totally clear: this is just a something we are considering. We may do it and we may not do it. Your feedback is welcome (but we still may do it even if lots of people say they hate it and we still might not do it even if lots of people say they love it). It is one of dozens of specs, some of which are for things that we are in the middle of implementing and some of which we might never do. Like I said, just an experiment!