[Talk-GB] highway_authority_ref vs official_ref

[Nathan Case]

 > On 09/04/2022 16:38, Dave F wrote:

 > I see nothing wrong with country specific tags, when appropriate. I 
think the argument to keep it still stands.

I agree that country specific tags are fine when appropriate (e.g. 
prow_ref). However it feels like the UK isn't alone in tagging such 
references on roads - so it's not a country specific thing. It therefore 
seems odd to me that we have a country specific tag.

I also think we're potentially creating confusion with having our own 
tag here. The example I gave of the UK wiki page saying we should use 
official_ref=* is one obvious issue 
(https://wiki.openstreetmap.org/wiki/Roads_in_the_United_Kingdom#Tagging_road_numbers). 



 > highway_authority_ref was chosen because it clarifies who created it. 
They're mostly used for internal accounting.

I think this goes with Robert's point about conflating the reference and 
who created/operates/is responsible for it. A separate tag should 
perhaps be used to describe who's responsible for the referencing.


 >On 09/04/2022 17:29, Robert Whittaker (OSM lists) wrote:

 > In the case of highways, there can potentially be multiple official 
reference numbers, with different purposes.

True - though I think it should always be assumed official_ref refers to 
the primary object it's tagged on (i.e. the road when tagged on a road). 
Using official_ref for a secondary usage would be odd (we assume 
properties belong to the thing being tagged) - so other descriptor tags 
(e.g. prow_ref) should be used.

The examples you give actually prove my point - we know it wouldn't make 
sense to tag a road with a PRoW reference, so we have a specific PRoW 
reference key. The same for a bridge. We make it clear the reference is 
not for the road by using an explicit secondary key. Whereas we use 
ref=* on major roads because it's safe to assume the ref key belongs to 
the road - as it's the primary feature.


 > I do have one minor issue with highway_authority_ref though -- I 
think it would be better if the key name refered to the reference itself 
rather than the managing body. So I'd prefer highway_ref rather than 
highway_authority_ref.

This makes sense to me and would be more global friendly. However, I 
think it would really invite *all* roads being tagged as such. This 
would probably end up getting this tag rendered, thus defeating the 
point of it.

I note that highway_ref=* has been used in the UK 
(https://overpass-turbo.eu/s/1hzq) though I think usage is mostly 
(exclusively?) by Robert.


It seems to me, we'd be better of using official_ref and perhaps some 
complimentary tag such as official_ref:source or official_ref:operator 
to describe who is behind the reference.





On 09/04/2022 17:29, Robert Whittaker (OSM lists) wrote:
> On Sat, 9 Apr 2022 at 16:43, Dave F via Talk-GB
> <talk-gb at openstreetmap.org>  wrote:
>> official_ref is used for objects other than highways.
>> It's is very vague, which is the main reason highway_authority_ref was
>> chosen.
>> In certain circumstances there maybe reasons for multiple 'official'
>> refs. It's much better to provide detailed, specific tags.
>>
>>> Should we consider retiring highway_authority_ref and replacing with one of the more globally accepted tags?
>> I see nothing wrong with country specific tags, when appropriate. I
>> think the argument to keep it still stands.
>> highway_authority_ref was chosen because it clarifies who created it.
>> They're mostly used for internal accounting.
> I agree that it's better to be more specific about what sort of ref
> we're referring to. In particular, it makes life much easier for data
> consumers. In the case of highways, there can potentially be multiple
> official reference numbers, with different purposes. For example, if
> the route is a Public Highway and a Public Right of Way, and it goes
> over a bridge, each of those could have its own official reference
> number. We have prow_ref and bridge_ref for the latter two. I think
> it's better to use a specific rather than a generic tag for the first
> one as well.
>
> I do have one minor issue with highway_authority_ref though -- I think
> it would be better if the key name refered to the reference itself
> rather than the managing body. So I'd prefer highway_ref rather than
> highway_authority_ref. The latter could be confused with a reference
> number/code *of* the particular highway authority that manages the
> road, rather than one that it's assigned to another object. More
> generally, in other situations, it's possible that the same authority
> might maintain multiple registers, and we'd want our key names to be
> able to distinguish between them.
>
> Robert.
>