[Tagging] Permanent IDs RFC (was part_of:wikidata)

Frederik Ramm frederik at remote.org
Thu Nov 30 07:20:43 UTC 2017


On 30.11.2017 03:13, Yuri Astrakhan wrote:
> Permanent IDs has been brought up several times, especially as part of
> the Wikidata ID discussion. I started a wiki page to outline the
> requirements and goals, but it might be incomplete, feel free to add /
> correct / comment.

See https://wiki.openstreetmap.org/wiki/Proposed_Features/UUID for an
earlier and somewhat failed idea.

Biggest issue IMHO that came up in the UUID discussion is that it is
unclear what the ID relates to, and mappers cannot be expected to handle
that topic in all its complexity properly.


Restaurant "Bella Italia" with well-known Michelin 4-star chef changes
its name to "Apulia" but otherwise stays the same. What happens with the
ID? What if someone has, somewhere, compiled a list: "All restaurants
named something with Italy" and linked to them by ID?


Same case as above, but restaurant (including chef and name) moves to a
different part of the city. Should the ID move? What if someone has
compiled a list: "Restaurants in 19th century buildings", of which the
old "Bella Italia" was a part, but the new one isn't?

To do this right, you would have to have different IDs for the same OSM
object - one for the "instance of restaurant" that happens to be here,
one for the building, one for the chef, one for the name - there's no
end. Somehow with a permanent ID you want to capture the "essence" of
something and stick the ID to that, but the "essence" of something is
often a combination of factors (name, location, cuisine...).

There are many other examples that illustrate that the very concept of
permanent IDs is hard to make work in OSM.


Frederik Ramm  ##  eMail frederik at remote.org  ##  N49°00'09" E008°23'33"

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