Err, back to the cobblestone topic:
Just my thought! I previously proposed “natural_cobblestone” for those uneven, unhewn, non-sett cobblestones. It’s not a real English word, but it should be quite clear what is meant, should it not? Another alternative: “unhewn_cobblestone”
I thought I’d posted this before, but must be mistaken.
If we’re just looking for a synonym to cobblestone to facilitate a transition, how about surface=cobbles? Or, if we want to get silly, surface=lumpy?
We are not looking for a synonym for the colloquial “cobblestone” but specifically this cobblestone made from natural unhewn stone. The clear distinction to cobblestone as generic term should be reflected in the name.
The problem with the word natural is that it might be understood as referring to substance, shape, or both. Cobble already implies substance, and we’re trying to identify shape, so maybe unhewn would be interesting (for example, unhewn_cobble or unhewn_cobblestone). It is not very well known though, judging from Google Images’ results.
Also, cobblestone is generally understood as having some binder (cement, mortar) holding the stones in place. Using cobble alone might be understood as loose stones.
In my dialect, cobblestone and cobble (singular) would imply a single, possibly unbound, item whereas cobbles and cobblestones would refer to a collection of them, possibly bound, possibly not. In my dialect it would be natural to refer to a cobbled street and peculiar to refer to a cobblestoned street. In my dialect, cobble implies substance, shape.and usage. Cobblestone doesn’t imply usage as strongly. “A street of cobbles is constructed using cobblestones” seems more natural (to me) than “A street of cobblestones is constructed using cobbles.”
Other dialects of English may differ on some or all of those points. Which may not be too important if we’re just trying to come up with a new term so we can deprecate the abuse of the old term. It’s not ideal, but one has to expect rough edges. 
So, unhewn beats natural and cobblestone beats cobble/cobbles.
So, how about unhewn_cobblestone then?
Glad to see some good suggestions, and at least to my non-native ears, unhewn_cobblestone sounds like a workable option that gets the distinction across.
Then should we also define hewn_cobblestone in order to slowly phase out cobblestone?
Absolutely! I think since an agreement has been reached here, what’s left to do is simply to document it in the wiki.
I will then also add it into the next StreetComplete version.
I haven’t seen “hewn_cobblestone” in this thread yet, so can you elaborate a bit what you would use this value for? Perhaps using the images used before (e.g. here) as a reference point?
Oh, I assumed that he mistyped it and meant unhewn_cobblestone. Basically, hewn cobblestone would be sett.
Nevermind, hewn_cobblestone would really be the same as sett.
Ah, good to have that cleared up. Glad that we’ve reached a consensus then. 
What remains is updating the wiki and getting mappers and devs to adopt this tagging. I’m happy to do my part for the latter by adding support to OSM2World.
Mh, perhaps ftbrien or Tordanik could add this to the wiki, since both of you extensively analyzed the wording over the time in the wiki, so you have the best idea how to exactly phrase it.
I am ready to do my part by letting StreetComplete use the new tag, but I would want to have it documented first.
Done. New definition, let me know if you agree/disagree:
The definitions sound good to me, thanks for adding them to the wiki.
What about the cobblestone:raised value you added a while ago, though? Wouldn’t that also fall under unhewn_cobblestone using our new definitions?
I’ll let you remove that if you think it should go. I added it because (1) nobody complained about it on the tagging list when I suggested it, and (2) many have pointed out, when referring to that image, that such pavement significantly affects traffic, particularly pedestrians and cyclists, and that such pavement seems to be intended to deter traffic.
I think I’d remove that then. The raised cobblestones would then really just be a subcategory of unhewn cobblestone and there is no clear line to distinguish these two (less raised vs more raised). Distinguishing unhewn from sett is already a good step forward.
Done: https://github.com/westnordost/StreetComplete/commit/bf387f21e75ef7b4c5e1738f25bdc16dfd59c48b
And removed cobblestone:raised from the wiki.
I have seen that in the wiki are strikethrough out and do not advise using the type of surface cobblestone:flattened to avoid confusion with sett and unhewn_cobblestone.
I think that in the discussion did not take into account a way of making pavements that is used in the south of Brazil and northeast of Argentina (see in overpass: http://overpass-turbo.eu/s/x19 ), which is called “brazilian cobbled style”, which is a variant of the known as portuguese pavement (see: https://en.m.wikipedia.org/wiki/Portuguese_pavement ).
The brazilian cobbled style is made with basalt stone and fits what can be defined as “cobblestone:flattened”: natural stone, crushed, smoothed surface, irregular, binder witk earth.
As you can see in the images:
https://wiki.openstreetmap.org/wiki/File:Empedrado_brasilero_1.jpg
https://wiki.openstreetmap.org/wiki/File:Empedrado_brasilero_2.jpg
For this surface, I think that the type sett (stones with regular format) or unhewn_cobblestone (uncut, with rigid binder) is not suitable.
For this, I request that consider modifying the wiki and not removing the “cobblestone:flattened” option to be able to use it on brazilian cobbled style pavement.
