[Tagging] Adding values to usage=* key for power transmission

Fran├žois Lacombe fl.infosreseaux at gmail.com
Tue Dec 16 22:42:37 UTC 2014


2014-12-16 17:50 GMT+01:00 Martin Koppenhoefer <dieterdreist at gmail.com>:
>
> could be. I am also generally for splitting different entities into
> separate objects, for the same reasons you describe below. Still with
> common values like "abandoned" in the railway key, stuff becomes less
> clear, and a combined object of power=* and railway=* could have its sense.
>

No it couldn't since the abandoned railway feature will have an end_date=*
key and the power=* one won't.

Merging two different feature in one is only a commodity question.


>
> when we don't know, we shouldn't judge ("an error").
>

We don't know because the features are merged. It is an error since we
can't distinguish them.
I'm sorry but a railway can't be transformed in a power line in reality.

In a quality point of view, when consumer can't make such a difference
(between a railway and a power line, but with many other stuff), there is a
QA issue.



> I think there is a big difference between "operator" and "usage": the
> latter is most probably intended to be a formal tag with a limited, well
> defined set of values, while the former is a free text field with any value
> possible. Mixing up "usage" in different contexts makes life harder for
> documentation, taginfo users, etc.
> Adding context by applying a namespace would help.
>

All keys in OSM are supposed to have free-text values. Let's start to
consider this question widely and tags as a whole. Not only for power,
railway, usage or operators.

The wiki gives information about which are most commonly encountered
together.
If tools aren't able to deal with this, they should be improved.

Secondly, if all keys have to summary the context in which they are used,
we'll obtain an endless loop.
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