On Fri, Apr 3, 2009 at 7:24 AM, Stefan de Konink <ste...@konink.de> wrote: > D Tucny wrote: >> Then shouldn't that be two nodes? with the atm one having a layer=1 tag? >> >> Similar to having a bar above a restaurant above a bank at the same >> position but on different floors... > > There are better examples probably; what should a supermarket that has a > post agency be talked like then?
one node with shop=supermarket, another with amenity=post_office? or you could draw the building outline, tagged with shop=supermarket and put a node inside it. or you could draw polygons for the floor area of the supermarket and a separate polygon for the post office. this sort of thing already exists for banks, but is tagged as amenity=bank, atm=yes. you could easily adopt this for other types as well: shop=supermarket, atm=yes. while stefan is right (there is no technical reason why we can't support duplicate tag keys whilst ensuring the tags themselves are unique), the pragmatic approach is to recognise that most clients and other bits of OSM software already use some sort of unique keyed map to store tags. it makes it easier to explain to people what is going on because there is one single amenity tag you can say things like "is the amenity tag set to supermarket?", rather than "are any of the amenity tags set to supermarket?". finally, while i don't doubt that multiple keys would reduce some data duplication, i have yet to see a compelling situation which can't be done without them. cheers, matt _______________________________________________ dev mailing list dev@openstreetmap.org http://lists.openstreetmap.org/listinfo/dev