@Something_B has recently edited the Wiki page for vending=bottle_return (to be used with amenity=vending) which has 2,145 uses to say that the tag is deprecated in favour of recycling_type=reverse_vending_machine (to be used with amenity=recycling) which has 19 uses. No reason for this was documented. vending=bottle_return continues to be used by iD tagging schema and others.
Has there been any discussion of this?
vending=bottle_return is extremely bad in semantics. Trolltag - OpenStreetMap Wiki describes why such tags is bad idea. amenity=recycling is actually fits, rendered on OSM Carto and maybe by other renderers also. amenity=vending_machine is just other things. If vending=bottle_return is OK, perhaps vending=banknotes for ATMs is also OK? Both vending machines and ATMs are machines.
Yeah but it still doesnât excuse you from simply deprecating it without a prior discussion (proposal or otherwise).
I can revert this change just now.
Iâve reverted the change. Besides the obvious one sided nature of the change, it isnât even clear if this is a troll tag.
Reverse vending machine not sell anything (as ordinary vending machine does), but doing an opposite: accepts bottles and issues tokens.
The point is that is that you get something of value from the exchange.
Hmm⊠Bottles instead of money? Ordinary VMs accepts money (banknotes, coins, debit or credit cards, etc.). But reverse VMs are different in this point.
It would be a good idea to move this into the amenity=recycling space. Machines that return money or a valuable token in return for recycling bottles, other glassware, plastic bottles, cans, etc. are increasingly common. Maybe a vending=bottle_return tag could be replaced by amenity=recycling + recycling:glass_bottles=yes + reward=cash/token/no/etc For machines accepting other recyclable goods, a suitable other recycling:*=* tag can be added.
There have been similar debates earlier:
Vending=bottle_return for coffee cups?
covering the issue of coffee cups as well as bottles and supporting the idea to use the recycling scheme instead of vending=bottle_return.
I probably agree that it would make more sense for this to be under ârecyclingâ than under âvendingâ, especially if we were creating a new tagging scheme from scratch, but to me deprecated means the community has discussed this and agreed on it, which also gives data consumers a chance to react. Not just that one person thinks itâs a bad idea. Itâs also confusing to mark it as deprecated on the Wiki while itâs in the iD tagging schema, without even telling them. If someone makes a proposal Iâll probably vote for it 
Yep, I fully agree to that and I did not want to support the undiscussed deprecation at all. Just wanted to connect to the earlier discussion not quite long ago.
so it isnât a vending machine. Nothing is sold.
That wasnât the question, the question was is it so far off that it is a (dangerous) troll tag.
how can a vending machine that is not vending not be a troll tag?
There are likely 100s of tags that âdonât quite fitâ (just consider shop=agrarian or worse craft=grinding_mill) contrary to troll tags (building=no etc), the question is if a naive interpretation by a data consumer has any consequences outside of purity concerns (contributors will be using presets so wonât be seeing the offending tags anyway), and I would say in this case no. There is just no useful way you can utilize amenity=vending without considering the vending tag (think soft drinks vs. parking tickets).
It is vending something: money, if you pay with bottles 
payment:empty_bottles = yes
cash_out = no
coupon_out = yes
Seriously:
Weâre lacking good tags for any amenity that is buying things. Car dealers buying used cars, second hand shops (which are not pawn_shop) buying used goods, jewelers buying goldâŠ
Bottle return machines are just one specific issue out of all of these.
I donât think âvending_machineâ isnât too bad for a tag - itâs just a machine that exchanges goods and money either one way or the other. Strictly speaking, even many parking ticket machines are not vending anything, on modern ones you just enter your license plate number and donât even get a ticket.
If we count only hundreds of tags out of tens of thousands (because if itâs hundreds you are also looking at many tags with small adoption), we can try to fix them all (and in the first place try to avoid them, most are the result of tagging for the renderer, because some main tag is already rendered hence people invent a troll tag to âuseâ this rendered tag in combination with something where it doesnât apply).
bottle return machines are not buying anything either. They neither sell nor buy anything.
For car dealers and second hand shops I agree there is no explicit tag (but it clearly is implicit)
Agreed. There may be some objects where it is really difficult to find a dedicated tag but that does not mean we should not try to do so if someone brings up such an issue.
In the given case a better tagging solution has already been presented so I canât see much of a reason not to go for it.