[Tagging] Solving the tag chaos (was: Re: Government buildings)

[Roy Wallace]

On Mon, Dec 7, 2009 at 11:07 PM, Steve Bennett <stevagewp at gmail.com> wrote:
>
> I care most about simply having a centralised resource that everything else
> trickles from. At the moment it seems that the four sources of tag
> information (wiki, renderers, editors, actual usage) can all feed off each
> other in any arbitrary direction. It's quite bizarre really. Almost any
> combination is possible:
>
> Potlatch implements a tag because JOSM does.

Sounds reasonable. (potlatch taggers becomes more consistent with JOSM taggers)

> One mapper uses a tag because he saw it on a wiki.

Sounds reasonable. (tagger follows same guidelines as other taggers)

> Someone documents a tag on
> the wiki because he saw it in Tagwatch.

Sounds reasonable. (so newbie taggers follow established taggers)

> A mapper uses a value because he saw
> someone else do it.

Sounds reasonable. (tagger follows other tagger)

All of these practices help to push OSM taggers towards consistency.
*In the absence of a centralised authority*, these practices are
necessary and, I think, effective. They complement each other. It's a
dynamic process, as it must be.

> It's fine that Mapnik and Osmarender (and others) render the same data
> differently. Having them *interpret* the same tags differently doesn't seem
> to have any benefits though.

What do you mean? I think the only problem is when there is *more than
one meaning per tag*. This is a problem and I'd be interested if you
have any ideas on how to avoid it.

> Having lots of people randomly use various tags
> not recognised by any renderer (or router) seems like a complete waste of
> time.

If you remove the word "randomly" from that sentence, I strongly
disagree. Tag the world - verifiably and explicitly - and the users
(renderers/routers/etc.) will follow. Inventing tags as necessary to
mark a feature with no documented tag is fun, and very useful. Just be
verifiable, and explicit. Use note=* to explain if necessary. The main
thing is to avoid the need for others to re-survey.