You can appeal rejected nomination. Even if appeal rejected, you can bring the case here for everyone to see. Staff might revert the decision with additional evidence
Some of those could be good depending on several factors (in the same vein, some could also be totally ineligible). Can always share your nominations here
Supermarkets are not typically eligible, although they can contain things that we can submit successfully like noticeboards showing local clubs and events. I’ve had quite a bit of success with this. They are often rejected by the community but accepted on appeal. Here are 2 examples which hopefully help with ideas on how to submit something at supermarkets.
Yes I have had community notice boards in these circumstances accepted.
Their function is exactly the same as one outside. In fact many of these are better as the shop actively curates them and makes sure the information is up to date and useful and community relevant.