don't warn about addr:housenumber without number when snc in Italy

[francians]

What steps will reproduce the problem?

1. create a node
2. set addr:housenumber=snc

What is the expected result?

No error in Italy

What happens instead?

Gives warning

Please provide any additional information below. Attach a screenshot if possible.

I suggest this change in mapcss:

*[addr:housenumber=snc][inside("IT")] {
  set ok_housenumber;
}

Please see:

https://josm.openstreetmap.de/changeset/15144/josm

URL:https://josm.openstreetmap.de/svn/trunk
Repository:UUID: 0c6e7542-c601-0410-84e7-c038aed88b3b
Last:Changed Date: 2019-06-03 00:05:30 +0200 (Mon, 03 Jun 2019)
Build-Date:2019-06-02 22:10:24
Revision:15155
Relative:URL: ^/trunk

Identification: JOSM/1.5 (15155 it) Linux Antergos Linux
Memory Usage: 1225 MB / 3541 MB (499 MB allocated, but free)
Java version: 1.8.0_181-b13, Oracle Corporation, Java HotSpot(TM) 64-Bit Server VM
Screen: :0.0 1920x1080
Maximum Screen Size: 1920x1080
Dataset consistency test: No problems found

Plugins:
+ OpeningHoursEditor (34977)
+ PicLayer (35030)
+ buildings_tools (34982)
+ turnrestrictions (34977)
+ utilsplugin2 (34977)

Tagging presets:
+ ${HOME}/JOSM/miopreset.xml

Validator rules:
+ https://josm.openstreetmap.de/josmfile?page=Rules/SuspiciousSwimming_Pool&zip=1
+ ${HOME}/JOSM/MyRules.validator.mapcss

Last errors/warnings:
- W: No configuration settings found.  Using hardcoded default values for all pools.
- E: Errore nella inizializzazione del test MapCSSTagChecker:

[Klumbumbus]

snc means "without number? Is it agreed in the italian osm community to use this tag for such houses? Is it documented somewhere?

[dieterdreist]

IMHO it is not ok, because „no housenumber“ is not a housenumber. I have made a proposal for nohousenumber=yes for these cases, but it is relatively new. I can confirm that people commonly use „snc“ when no housenumber has been assigned (it literally means no housenumber = senza numero civico).

[Klumbumbus]

We discussed similar cases "S/N" and "bb" before in #17486. For "S/N" we still warn but we excluded "bb" in Bosnia Herzegovina as it is used there in official documents. If "snc" is not used in official documents by the government in Italy I would too keep the warning for "snc" because then it is much likely "tagging for the QA tool".

[dieterdreist]

„official documents“ is very vague, I am sure there are many snc in official documents, but it doesn’t make it a housenumber. There may also be a habit to add the term into housenumber fields in forms, but again, this is just a shortcoming of those forms and not a sign that this would be a housenumber. The nohousenumber in analogy to noname=yes is a defined representation of the fact that no housenumber has been assigned. What would you say if people added “no streetname” into addr:street? I encourage you to rethink your decision on the Bosnian case as well.

[francians]

osmose Devs agreed about this change request too:
​https://github.com/osm-fr/osmose-backend/commit/30df15ba73d3144c0f03a2dc0151890616a09d48
It is common in industrial areas