[Tagging] Facts and opinions
sfkeller at gmail.com
Thu Jan 10 01:23:13 UTC 2019
As one of the originators of this thread I'd like to second that the
Wiki is important. It's not only a documentation tool but also a
communication. We all need patience with Wikis and it's curation and
users - like we e.g. have patience with when we're discussing things
about iD presets or iD functionality (like Copy&Paste which remained
unimplemented since 2013 - hint to Bryan :-))
In addition I'd like to draw your attention to my three points
expressed in my original thread entitled "Values in
namespaces/prefixes/suffixes Considered Harmful - Or: Stop
over-namespacing and prefix-fooling". IMHO we're on a critical
crossroad because of the new-style namespaces (also favored by the
unique multiCombo functionality in iD among others):
1. How to combine concepts?
2. How to group (sub-)tags?
3. How to handle multiple values?
Namespaces are an attempt to all these.
But IMHO for handling groups (2), there's the Wiki (!) - and Presets.
And for handling multiple values (3) I'd still favor semi-colon
separated as long as possible.
As said, the currently growing over-namespacing and prefix-fooling is
detrimental to the OSM schema and turns key/value ad absurdum.
Regarding (2), namespaces are not meant to group values, but to group
attributes/keys! And regarding (3), pseudo-namespaces are not stored
in one bit, in contrary: those long tag tag strings blow up e.g. the
attribute storage in Vector Tiles unnecessarily.
I've quickly analyzed Switzerland and found e.g. following
pseudo-namespaces containing significant amount of Upper-Case keys
(which is a smell of being values smuggled in keys, since keys should
be lower or unsiginificant case): service:* but also currency;*,
payment:* and fuel:*.
Here once again some considerations.
Instead of this "a hodgepodge of different ways of tagging and
potential for 100s of keys" as Simon said:
All of the above could or should be this:
And as a last comment: The addr-namespace is a good example of namespacing!
But namespacing is not the only means we have to group tags: we also
have Presets and Wikis documentation!
Am Do., 10. Jan. 2019 um 00:43 Uhr schrieb Warin <61sundowner at gmail.com>:
> On 10/01/19 10:13, Tobias Knerr wrote:
> > On 07.01.19 16:12, Bryan Housel wrote:
> >> I encourage everyone to just disregard everything that’s on the wiki and go by what taginfo says as far as how the tags are used and what the accepted values are.
> > The wiki is an invaluable source for understanding OSM tagging, and I
> > use it all the time during mapping and when coding software that works
> > with OSM data.
> > Taginfo is an awesome resource as well, and I use it almost daily, but
> > it cannot fully replace the wiki. It tells you that foo=bar has been
> > used thousands of times, but it doesn't tell you what that tag means¹.
> > It also doesn't tell you about the conventions for its use (default
> > values, directionality, lots of other essential details). Ultimately,
> > Taginfo isn't documentation – the wiki is.
> Taginfo does not tell me what landuse=clearing is. It only tells me there is some of use of it.
> There is no wiki page on it so there is no help there.
> The next thing to do is contact the mappers.. tried that .. one response told me to go to another channel - did that, nothing worth while.
> Contact a mapper .. no response there either ...
> Best I can do then is use my brain to think about the words and the mapping context to come up with what I think they meant by it.
> My conclusion is - if it is not documented on the wiki .. it does not exist.
> > Besides documenting current tagging practice, the wiki is also a useful
> > tool for coordinating and spreading new ideas (even though the specifics
> > of the process can be controversial at times). If you're not a software
> > developer or one of a few highly respected community members,
> > discussions on community channels and wiki proposals are pretty much
> > your only good options to make your genius tagging idea known to the
> > world. Without this first step, that idea is unlikely to get enough
> > traction to even show up in Taginfo to a meaningful extent: Using the
> > tag yourself only gets you so far.
> The wiki also help differentiate between things that are close in appearance to the casual mapper.
> Things like a netball court can be mapped as a basketball court, until you can see the difference and that is on OSM wiki pages.
> > For all these reasons, I consider the wiki a key asset to our project.
> > As a result, I spend a lot of time improving it, as do many other
> > community members. It hurts to see that some developers of core OSM
> > infrastructure seemingly value these contributions so little. To me,
> > people discussing and documenting our data model are a vital part of our
> > community. So are software developers, of course! It's my belief that
> > the project can only thrive if there's mutual respect between these groups.
> > Tobias
> > ¹ Taginfo actually does provide a definition, but that's because it
> > extracts them from wiki pages.
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