This list is for things that are not appropriate to post on iNat. It is a question that has come up a few times and I thought it would be handy to have the list in a single wiki post. They are not always equivalent to posting on iNat and I will go a little outside the box.
State of matter - mineral. Geology, Rocks and even fossils.
State of matter: Man-made litter. Plastic, cigarette, paper, can, bottle, etc.
State of mind Existential observations, ideas, aspirations and dreams. Inform, inspire, ignite change for the common good. (If not right here on the iNat forum)
I like this one about climate change
GPS data like tracks or POI (point of interest)
Something I would like to see, but cannot find: anthropology. Cave paintings, middens, stone tools, ruins, historical evidence of ancient humans, etc.