OpenStreetMap
I've noticed that the use of identical boundary relations may cause display issue, witness 95672 and 95671. The first is a postal code (at administrative_level=8 for some reason) with name=3060. The other is the suburb (administrative_level=10) with name=Fawkner.
The result is that depending on zoom the displayed name will alternate between "Fawkner" and "3060". Surely there is no need to list name=3060?, and arguably a single relation could be done to cover both? Also I might be crazy but are postal code realy independent administrative units in need of their own boundary definitions?
Discussion
Kommentaar van Skippern op 9 November 2009 om 01:04
IMO postal codes should be marked on the map (though not rendered in an ordinary map). They should also be marked with boundaries, not boundary=administrative, but some other form as it represent a practical division of a distribution system, and not different administrations. For example, in Norway, there are only two levels of administration in the postal system, one national and one regional, though there are several postal codes within the area of each regional postal administration.
IMO postal code relations and administrial boundary relations should not be combined, even if they follow the same line. Though they should be tagged differently, so that renderers does not confuse them.
Kommentaar van Circeus op 9 November 2009 om 01:39
I completely agree about the usefulness of indicating postcodes, but I am dubious about the necessity of giving them separate relations when they are identical to an existing one. Just changing the boundary type would fix the problem, though. boundary=postal would likely be sufficient. After all these will almost certainly never be displayed on the default OSM map, so whatever value is chosen really doesn't matter much.
Kommentaar van seav op 9 November 2009 om 06:09
If the admin boundary has its own postal code as this example seems to do, why not just tag the admin boundary relation with an additional addr:postcode tag?