[OSM-talk] Tagging climbing routes and scrambles

[Steve Hill]

On Wed, 23 Apr 2008, Andy Robinson (blackadder) wrote:

> The point has been made by others that the namespace here is unnecessary. We
> know what length= means here so the climbing namespace is superfluous
> because what you are tagging is a climbing route.

I'm aware the issue is contentious, but no one has said anything to 
convince me that namespacing isn't a good thing (certainly nothing showing 
why it is a bad thing).

> Start to end of section as one way (there may be more than one section in
> the route, some climbing and some scrambling etc).

I had considered specifying that each pitch (section) must be a different 
way, but concluded that it probably made things unnecessarilly difficult 
since you'd end up with a big cluster of nodes and ways in a very small 
(horizontal) area.  Of course, there is nothing stopping people from 
sticking nodes in the middle of the way if that is sensible for specific 
routes (i.e. ones with a large horizontal component).

> climbing routes are no different.

They are different in the fact that they have a much greater vertical 
component and a much smaller horizontal component to almost any other OSM 
features, which makes handling the data in a 2D environment (such as JOSM, 
Potlatch, etc) more difficult.  This certainly needs to be taken into 
consideration.

> adjectival:gb= (assuming the same route at the same location requires
> alternative country grading, if it only applies within the country where the
> route is located then the gb would not be required)

Only the British system has the separate adjectival/technical grades - 
other systems have a single grade to describe the route (the exception 
being YDS, which has 3 separate grades to describe different aspects of 
the route).

It is common to list several different grading systems for the same route 
as well - for example, in the UK, sports routes are often given grades for 
both the British and French grading systems.

> Anything that has lots of namespaces, abbreviations or other non-obvious
> tagging names makes it much more difficult for data contributors to easily
> add tags.

On the contrary, namespaces make it easier to look up the definitions of 
tags, etc. since there is no chance of being confused with identical tags 
from a different context.  I really dislike the way that, without prior 
knowledge, it is impossible to determine the context of the tags if they 
aren't namespaced.

In your example, the context is given by the "footway=climbing" tag.  But 
the only way you know this is providing the context of the other tags is 
by some fairly arbitrary prior knowledge - how do you know that the 
context wasn't provided by the "rock=limestone" tag instead?

> Simple and logical appears always to work best.

Indeed, I agree.  But we differ on what we believe is "simple and logical" 
- I think clearly declaring the context of the tag is much more simple and 
logical than having a mess of identically named tags, potentially meaning 
totally different things depending on a context provided by another tag 
which isn't obviously providing the context.

If there was a *single* "type=" tag that always describes the context of 
the whole object, then I might agree that namespacing is unnecessary, but 
there isn't, so I don't. :)

e.g. type=highway:motorway, type=waterway:river, type=railway:line, 
type=piste, etc.

  - Steve
    xmpp:steve at nexusuk.org   sip:steve at nexusuk.org   http://www.nexusuk.org/

      Servatis a periculum, servatis a maleficum - Whisper, Evanescence