[OSM-talk] Post code areas

[Richard Weait]

On Thu, Apr 1, 2010 at 1:01 PM, Frederik Ramm <frederik at remote.org> wrote:
> Brian Quinion wrote:
>> boundary=street_postal_code | district_postal_code | city_postal_code
>> street_postal_code = 425253
>
> I'm having difficulties in grasping this concept. In Germany we have
> 5-digit post codes, and the associated regions vary in size depending on
> how densely populated an area is. So a five-digit code might sometimes
> encompass a whole region, sometimes a town, sometimes just a quarter.
> That doesn't technically make them different kinds of post codes, and
> any labeling like "street/district/city" would be purely the mapper's guess.

Wikipedia tells me that partial Canadian Postal codes are useful to
the post office[1].  In K1A 	0B1 - K is the postal district, K1A is
the Forward Sortation Area and 0B1 is the Local Delivery Unit.  Sounds
like "internal use only" to me.

> Are there really countries where if you ask someone for their post code
> they will reply "do you mean my street post code or my district post code"?

In my experience, in Canada folks will only answer with their complete
6-digit postal code (If they know it at all.)

In the US, Zip Codes changed from 5 numeric digits to 9 numeric digits
in 1983[2]. In my experience I am much more likely to hear just the
old 5-digit Zip Code rather than the Zip+four that could be considered
the official zip code in conversation.

[1] http://en.wikipedia.org/wiki/Postal_codes_in_Canada
[2] http://en.wikipedia.org/wiki/Zip_codes