In that case, the more colorful synonym is “bridge to nowhere”. man_made=bridge nodestination=yes? 
My hometown used to have a pedestrian bridge to nowhere, caused by the building at one end being very carefully demolished. It was mapped as a bridge; I don’t think it ever occurred to anyone to tag it as a pier before it was finally demolished.
And the Scheveningen Pier leads to a restaurant and bunjee jump crane, so it’s a bridge, but nobody would map it as a bridge. Just saying, it’s not black&white, piers&bridges.
Very academic discussion!
The Scheveningen pier is very clearly a pier, even if it may not have the function of a landing stage (I don’t know exactly). A very typical feature is that it is built on piles.
And the bridge in Avignon is and remains a bridge, even if it no longer reaches the other side of the river. Of course, bridges can also be built on piles, but this one has very typical characteristics of a bridge construction. And the structure bridge does not suddenly become a pier just because the connecting function is removed.
And a building=church remains a church even if part of it has been demolished and it is no longer used as a church.
It is not enough to pick out just one feature to judge what kind of building/structure it is. But actually, common sense should be enough.
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Construction of bridges and piers varies widely. You can’t tell by the construction if it’s a pier or a bridge. Well, if there is no path on it, it’s probably not a bridge, and if there is a road on it it’s probably a bridge. Mostly this coincides with there being a destination on both sides or just one side. All of these can change over time, and public opinion has its own dynamics.
I would say, if the thing connects two shores and it has a road or path on, it’ s bridge, and if the thing ends in limbo for whatever reason, it’s a pier, and when in doubt because of history or whatever, let someone else map it and be happy with a pier in mint condition mapped as a bridge in ruins! Because both are true.
Was it actively being as a way for people to walk out to the middle of the street before it was finally demolished? My guess would be that it wasn’t. In this case, people are actively using Pont d’Avignon to walk out to the middle of the river. Just like they would be if it was pier. I’m assume you’d agree that whatever something was used for in the medieval times, that however it’s currently being used by the local, currently exiting, community should also matter. Especially since from what I can tell there’s no plans to fully restore it. It’s not like there isn’t tags that can be used to show it was a full bridge in 1100 that would also allow for tagging how it’s currently being used either. It’s just that certain people seem to think that tagging it as a pier would be insulting to Louis VIII or some nonsense.
Interesting idea. If there was a church building that was a turned into a second hand store would you advocate for continuing to tag it as building=church + amenity=place_of_worship or would it be fine in your opinion to re-tag it as building=retail + shop=second_hand?
if it was a church building, it likely remains a building=church also after a shop opens inside, maybe you had been thinking about building:use?
Yes, this is common mapping practice and so documented in the wiki!
Of course not! But it is also documented that way:
No! If the building was built as a church and also obviously looks like a typical church, then the correct tagging for your example would probably be:
building=church (without "amenity=p_o_w" of course)
building:use=retail
shop=second_hand
And it is the same with this bridge:
If it was built as a bridge and obviously looks like a bridge, then the structure is a bridge and not a pier. And if a part is destroyed, then it is historic=ruins, regardless of whether the part that still exists has been restored. Only mistake: the bridge is currently mapped as building=bridge. This is tagging for the renderer. It should be man_made=bridge. And it should be added: bridge:structure=arch
Yes, I can! Maybe not in every case, but in most. When I type bridge or pier into an image search, I see images that I can distinguish from each other. I can clearly distinguish: this is a bridge and this is a pier.
Oh, there are also bridges for supply lines. A bridge=aqueduct is a typical example.
No, I don’t think so. It depends on what you generally think the building tag is for though. IMO it’s to tag the current usage of a building, not what the building was originally built for. Literally no is going to have access to that information in most cases and it doesn’t provide anything useful anyway. Like most people could super care less if their local record store is located in a building that was originally meant to be a chiropractor’s office. Maybe it’s just me, but I feel like you’ve really lost the plot if that’s something your super concerned about 
I mean, sure. I guess that’s what the Wiki says. In the United States church buildings can be pretty generic. Like take the average Jehovah’s Witness Kingdom Hall. From a distance they usually look like mid-tier dentist’s offices. So if one ever turned into an actual dentist I doubt anyone would continue tagging it as a church building regardless of whatever the building=church article says. I’ll concede it’s probably different for a church building like St. Peter’s Basilica though. But church buildings in the United States just don’t tend to have that unique of a design or be that historically important. So I don’t think it really matters that much here. Not to mention whatever the Wiki says should usually be taken with a grain of salt anyway.
To make the comparison work, the church would have to have been in ruins, then partially restored as the lesser part of a former church, specifically for the current use as a touristic attraction in mint condition, while all the remnants of the ruins, including the main body of the former church, have been totally removed.
I think I would not see it as a church in ruins any more. The remaining structure has been repurposed and restructured explicitly for the new purpose. But hey, if it’s not in my back yard, it’s not my call.
And what is that?
The “stairway to nowhere” on the left of the picture?
Not a bridge, because it connects nothing?
I think it’s a dock for small airborne vehicles.
Did you forget a smilie?
Yeah… just got boostered, that must be it.
Next try: I would call that a hangout.
: wink :
Only mistake: the bridge is currently mapped as building=bridge. This is tagging for the renderer.
I think this bridge could be considered a building under many aspects, there are actually enclosed rooms (a chapel) in the bridge.
No, I don’t think so. It depends on what you generally think the building tag is for though.
sure, and it is established what the building tag is for, there is no room for your interpretation under the “building” key. Have a look at what Mammi71 wrote.
a building=church is a building built to be a church, it doesn’t become a church because there is a church inside, because it isn’t about use, it is about building typology.
The chapel is already mapped as a separate object. It looks like a chapel and is tagged as a chapel.
Supplementary: yes, the “churches” of Jehovah’s Witnesses are a particular problem because they do not fit into this typology and were often converted buildings of an originally different typology. And this is not only the case in the United States.
And that is why, precisely why, it is so explicitly described in the wiki.
To quote myself “Literally no is going to have access to that information in most cases and it doesn’t provide anything useful anyway.” So it’s less about “my interpretation of the tag”, which isn’t actually that far from the tag’s description BTW, and more about the realities of how people actually decide to tag something. Which obviously isn’t as simplistic or clear cut as you or a random note on a Wiki article is making it out to be. Like if someone is mapping a house they are probably going to consider the surrounding context as much as, or more then, what the building was originally built for when deciding how to tag it.
It’s funny how if I quote the Wiki people will accuse me of Wiki lawyering, but if I try to have a nuanced position about something I get attacked for having my own interpretation of things or whatever. People are clearly going to find something about what I say to take issue with regardless of what my position is.
The same goes for Christian Science Reading Rooms and the Church of Scientology. Although to a lesser extent then Jehovah’s Witnesses. But none of them tend to occupy buildings that were purpose built to be churches. I think it’s perfectly fine to still call them church buildings in the meantime though. Otherwise, it just seems like a weird form of religious intolerance or something. “Sorry Jehovah’s Witnesses, but we can’t tag your kingdom hall as a church building because it was built to be a law office 80 years ago. I know it’s been a kingdom hall for the last 60, but hey, topology man ”
It would’ve been prudent to note that there is currently Voting going on Proposed features/Historic - OpenStreetMap Wiki (also note that initial votes have been nullified by proponents; so if you voted before, you might have to do it again).
(although I find proposal quite confusing what is actually being proposed in this iteration and why, even after reading all this discussion here and on tagging mailing list / second thread).
I deeply object to the fact that this proposal was re-opened for a vote without the standard courtesy of community notification.
