I really like the idea of linking between OSM and an external database which contains non-geographic data. I just saw this thread now but I see a heated discussion has been going on for a while. I think one of the big benefits of the link is not just identification of on object (McDonald's) but also the added detail that can be included beyond what is possible in our tagging scheme, such as the logo or a nice story about the history or even today's specials (for all those McDonald's that have a daily special).
I'd like to make one suggestion that I suspect won't go over real well. But it is a thought people should consider. There is a natural mechanism for tying information to geographical locations - the address. There is a particular McDonald's restaurant in the external database and it will have the postal address 1248 Fairlawn Ave, Morgantown, WV, USA. This connects it to the OSM database. This address concept extends beyond postal addresses. The "ref" tag should be used for this purpose. For example, a transit route should have a reference to say what route it is. This should be the publicly available name for the route which is also used in the external database. There are many other ref values that serve as addresses - Gate 7 in an airport. Room 325 in a building. Exit 12 on a highway. Aisle 5 Shelf 2 Bin A in a grocery store. The list is endless. Back to the McDonald's case, in addition to address I am sure there is a franchise number. And there is the Value Added Tax ID which was mentioned (which I have never heard of). Admittedly we may need to improve our ref tagging to make sure it is adequate to specify objects in this manner. And some of these ref values will be difficult to get. Most notably this method would require the value be set in two places, OpenStreetMap and the external database. But the benefit is that the value selected is a meaningful value in its own right, not just within the context of a single external database. These values were defined before OpenStreetMap or the external database came along. And they allow linking between OpenStreetMap and any number of external databases. That may be the biggest benefit. Dave _______________________________________________ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
