[OSM-dev] FW: Screenshots from OpenStreetMap-Carto spot checking

Ed Loach ed at loach.me.uk
Fri Dec 21 08:40:09 GMT 2012

(Let's see if my bounce issues are resolved)

-----Original Message-----
From: Ed Loach [mailto:ed at loach.me.uk] 
Sent: 20 December 2012 08:46
To: 'Toby Murray'; 'dev List'
Subject: RE: [OSM-dev] Screenshots from OpenStreetMap-Carto spot

Toby wrote:

> I was doing some poking around yesterday and noticed that county
> borders (admin_levl=6) aren't being rendered at zoom 9 and 10. 

The wiki instructions for administrative boundaries are designed I
think to help renderers at whatever point in time the instructions
were written. Each boundary relation is meant to have the
boundary=administrative tag and the correct admin level tag. Each
way is also meant to have the boundary=administrative tag and the
lowest value of admin_level (so a boundary which is a member of say
admin level 4,5,6,8 relations would get 4). I have always assumed
that the way tags are only there to make things easier for renderers
as in theory it can also be determined from the relations the way is
a member of.

If it is possible, this carto switch might be a good time to make
the relation tagged levels take priority and the way tags
unnecessary for relation based boundaries (though perhaps still
relevant for boundary ways that aren't in relations). I've spent
quite a bit of time in the past trying to keep the GB boundary tags
in line with the wiki documentation, though haven't bothered


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