[talk-au] Victorian Vicmap Address Import Proposal

[Andrew Davidson]

On 19/5/21 2:48 pm, Andrew Harvey via Talk-au wrote:

> 
> 2. Should we also import `addr:suburb`, `addr:state` and `addr:postcode` 
> tags? I'm proposing we do.

Please don't do that. Now that we have a complete set of admin_level 10 
boundaries in Australia addr:suburb is now redundant.

> Given postcode regions aren't mapped, then adding these to the address 
> should be very helpful.

Postcodes can be added once to the level 10 admin boundary or as a 
separate postal_code boundary if they don't align.

> `addr:state` is less important given these addresses fall within the 
> Victoria state admin boundary already. The wiki touches on this saying 
> "A few mappers consider higher-level tags, or even addr:city=* as 
> redundant, since they could be calculated from the respective boundary 
> relations they are contained in (if present and valid). However, such 
> practice has severe disadvantages and can lead to wrong results."

If you read the explanation on the talk page this does not apply to 
Australia because we have contiguous postal areas.

> Either way, I don't think it matters too much, but since it's not 
> harmful to include, and might provide some benefit, then we may as well 
> include `addr:state`?

It is actually harmful because you have to maintain the same piece of 
information in thousands of places. Not only that having multiple 
sources of information seems to confuse Nominatim. On the other hand 
adding it has no real benefit, so I would suggest that you don't import 
anything beyond the street name.

> 3. `addr:suburb` vs `addr:city`.

The addr:city is for countries where the postal address has the concept 
of a postal city. As we don't have that in Australia then we don't need 
to have this tag.

> 
> Both tags are in use within Australia. According to taginfo 
> (https://taginfo.geofabrik.de/australia-oceania/australia/search?q=addr%3A 
> <https://taginfo.geofabrik.de/australia-oceania/australia/search?q=addr%3A>) 
> within Australia addr:suburb occurs 521 ,671 times and addr:city 562,542 
> times.

About 99.99+ % of those addr:city are from the Brisbane address import 
and I would view that as a mistake rather than a reason to perpetuate 
this elsewhere.