[Imports] [Talk-cz] CzechAddress Import

"Petr Morávek [Xificurk]" petr at pada.cz
Thu Mar 13 00:42:35 UTC 2014


Hi,
I'll start by saying that it's not that simple as some (even Czechs)
suggest. I do think the suggested tagging is mostly the right way to go,
although I don't really care if addr:suburb or addr:borough is used for
"městská část" - addr:suburb is more used and fits the purpose within
"OSM dictionary", but addr:borough is probably a better match in English
(and British?) dictionary.

I'll try to explain the meaning of the used terms.

*Obec* ("municipality") - is a "well" (more to it later) defined area
with its own administrative body - closest term in Engslih is probably a
town hall. That's what we want to put in addr:city. (And that's what we
have as admin_level=8 boundary relations.)

*Část obce* (literally "part of municipality") - this is a subdivision
of "obec". The relation of "obec":"část obce" is of type 1:N. The "část
obce" can manifest itself in many different ways - in the countryside it
is most usually what you would call a village (it has its own sign post,
people use it as "Oh, you're from 'Část obce A', I'm from 'Část obce
B'."), in urban area it's usually (not always!) a name of the settlement
annected by a larger city. It has no administrative (or political) body
of its own. It does NOT have any well defined boundaries. It is defined
by the list of address points (more precisely, buildings), thus you can
create an envelope boundary based on this, but you cannot draw a well
defined border line. And to be honest, I'm not really sure if the
envelope driven boundaries will or won't overlap. This entity has one
very important property - the conscription numbers are unique within
"část obce", so in principle the only thing you need to unambiguously
identify an address point is the name of "obec", "část obce" and
conscription number (note: this is usually not the way the address is
written). That's what we want to put in addr:place.

"Městská část" ("borough"/"city district") - this is used only in larger
cities (but not all of them), this is a subdivision of "obec" parallel
to "část obce". The relation of "obec":"městská část" is of type 1:N,
relation of "část obce":"městká část" is of type N:M. This entity has
its own administrative body - something like a town hall, but it is
subordinate to the town hall of the "obec". That's what we would like to
put into addr:suburb or addr:borough.

"Katastrální území" ("cadastral area") - another type of subdivision of
"obec". The relation of "katastrální území":"obec" is of type 1:N, both
"mětská část" and "část obce" have relation of type N:M. This entity has
a well-defined boundary and we have it in OSM as boundary relations with
admin_level=10. We don't plan to add any addr related tags to address
points since its name is not usually (read: "never") used in address.

Post code - this is mandatory part of the address, it is used not only
by the national post office, but by other delivery services as well.
Postcode and all of the above entities (including "obec" /
"municipality") have a relation of type N:M.

The last part of the puzzle is a "street name". One street may cross
several "část obce", "městská část" and "katastrální území" (N:M
relation), thus in principle it IS possible to have two houses with the
same conscription number in the same street and municipality (although,
I did not check if this really happens somewhere, but I doubt it).

--

This complex system of subdivisions has some funny bits to it, e.g. this
building:
http://vdp.cuzk.cz/vdp/ruian/stavebniobjekty/7603991
It belongs to "část obce" Dědek, which is part of "obec" Živanice. But
it lies within boundaries of "katastrální území" Neratov, which is part
of "obec" Neratov.
Now you're probably screaming something like "WTF?!?", but well that's
the way it is, don't blame the messenger ;-)

-- 

Back to the address scheme... I'm talking from my own experience when I
say that our post is capable of delivering almost anything :-)
The most usual way of writing an address is
[Street] [Number], [Obec] [Post code]
or
[Část obce] [Number], [Obec] [Post code]
But other variations are also permitted (and some institutions even
require them), like:
[Street] [Number], [Městská část] [Post code]
[Street] [Number], [Post office name] [Post code]
[Část obce] [Number], [Post office name] [Post code]
...
On our ID cards the address is written in form of:
[Obec], [Část obce]
[Street - if applicable] [Number]


Best regards,
Petr Morávek aka Xificurk



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