[Tagging] The endless debate about "landcover" as a top-level tag

Christoph Hormann osm at imagico.de
Sat Jun 9 08:00:02 UTC 2018

On Saturday 09 June 2018, EthnicFood IsGreat wrote:
> I have been editing in OSM for almost four years, and I've been a
> member of this mailing list almost since then.  I read every single
> post. During that time I have never seen what I would consider a
> consensus reached on anything.  I'm not sure it's even possible.
> [...]

I think you are misunderstanding the concept of consensus here as it 
applies to OSM overall.  This does not require explicit agreement by 
all mappers, this would not be feasible.  Consensus is more about 
finding the overall or on average most satisfying approach to a 

> I've seen several tags debated more than once in four years.  I can
> only assume that each time, a different group of people get drawn in
> to the discussion, unaware that the issue has been debated before,
> with no resolution.  This cycle is doomed to repeat itself over and
> over, as long as OSM proceeds the way it is.  A waste of time and
> effort!

If you try to follow evey tagging debate here and on the wiki i agree, 
this is very frustrating and wasteful.  I prefer to see this as a 
statistical process.  We are a diverse global community, it is 
unavoidable that every topic of significance gets discussed many 
times - in different languages and in different settings.  And often 
even more than once in the same setting as you mention.  Everyone is 
free to ignore any of these discussions and should do so when it seems 
wise to do that.  But every now and then one of these discussions 
yields a new idea no one had before and in some of these cases someone 
picks up this idea and communicates it further so it might be adopted 
by the community at large.

I have learned to mentally filter out the discussions here centered 
around key systematics for example over time (though i am sometimes 
complementing if there are some keywords i could use for automatic 

> I don't see how OSM can work well when mappers are free to tag
> however they want.  Different people have diametrically opposed ideas
> about how things should be done.  For example, some people think the
> meaning of a tag in OSM should be the dictionary meaning of the word;
> others are okay with a tag word having a "special" meaning in OSM. 
> How is a mapper to decide?  There is no consensus on this issue. 

I think this confusion comes from the fact that you are looking for 
structure where there is none to be found.  Freedom to tag means the 
mappers can decide on a new tag in any way they like.  If they choose 
badly other mappers are less likely to pick up their choice and make it 
a widely used tag.  Yes, very wasteful again for someone who is used to 
a top down approach.

Maybe the best analogy for tagging in OSM is biological evolution.  You 
could also kind of argue that evolution can't work with individuals 
mostly dying at random and arbitrary genetic mutations deciding on how 
things develop.  Bio-engineering would be so much more efficient - 
except that we would be way over our heads with the decisions what 
genetic traits are actually advantageous in the grand scheme of things.

This analogy also means that competition is essential for progress in 
OSM.  We need more competition on all levels - both from outside OSM 
(which is why the idea of a fork with a more structured tagging system 
is a good one) and from inside in form of more map styles featuring 
different sets of tags.  The way OSM works depends on these things as 
incentives for progress - just like evolution depends on ecological 
niches and competition for creating diversity and selection pressure.

> Although OSM has a policy of "any tag you like," based on the posts
> I've read, it seems most mappers want some guidance when it comes to
> tagging.  I deduce this from all the posts I read from contributors
> having to do with editing and refining the wiki.  However, there
> isn't even agreement on the purpose of the wiki.

You probably have - based on this particular discussion - a somewhat 
exaggerated impression of the lack of agreement.  There is a small but 
voiceful group of people who like to push certain ideas in this matter 
and are willing to bend or ignore both established rules and the vast 
majority of mappers to do that.  But there is no serious question on 
the main purpose of the tag documentation part of the wiki, this stems 
from the very principles of OSM.  If some people ignore those rules or 
question them in dicussions this does not mean they cease to exist.

And i think you are not correct with your assessment of what most 
mappers want.  Most mappers are not native English speakers so they 
would not receive most guidance created by some tagging authority 
anyway.  Most mappers want tags that represent what they see in 
reality, not something that fits into the systematics thought up by 
some committee of people from Central Europe and North America with no 
clue about the diversity in culture and geography world wide.

Christoph Hormann

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