A sentence was recently added to the wiki [http://wiki.openstreetmap.org/wiki/Key:place] stating that the tag place=city should be used for legally defined cities in countries where such a status exists. This is superficially attractive but it gives rise to problems. The key issue is that place names, like roads, naturally form a hierarchy, and that the tag place=city is similar to the tag highway=trunk.
For instance, the category in the United Kingdom includes Wells, which has a population of 10,000 and which the Collins New World Atlas leaves out of its 1:3,000,000 map of the British Isles. This is similar to the road category of Bundesstrasse (nationally maintained road) in Germany, which includes some quite small roads while omitting ones that are much more important. If (say) highway=trunk was used for such roads a map generated only from OSM data without an outside cheat sheet gives a warped idea of roads in Germany; OSM solves this problem by not using a distinct level for these roads. Using tagged population figures as a substitute to guide renderers has been suggested but it brings its own problems because people will expect them to be more broadly useful and figures may either be out of date or it may be unclear what area is being counted. -- Andrew _______________________________________________ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
