Hi, On 02/23/2015 02:43 AM, Kurt Blunt wrote: > Right now, tags serve two distinct purposes. There are attribute tags > like name=Wall Street, and there are category tags like > amenity=parking or aeroway=helipad.
This works for many things but not all; the border can be blurred. You will not be able to fit every key into your "category or attribute" schema. > Many tags don't even make sense. What does highway=track mean? Is it > a highway that acts as a track? A track is clearly not a type of > highway. A track is just a track. And if you travel along a dark track in the night then you might be robbed by a highwayman. > A contributor is left to feel like > an idiot for not understanding the logic behind this system. Woe betide all who mistake highway=unclasssified for a street that lacks classification. > For these reasons, I believe there is a case to be made for an > overhaul of category tags. My personal opinion is that we should get > rid of super-keys altogether and instead promote all categories to > keys with empty values: "amenity"="reception_desk" becomes > "reception_desk"="", "highway"="track" becomes "track"="", > "aerialway"="gondola" becomes "gondola"="", "barrier"="city_wall" > becomes "city_wall"="", "historic"="city_gate" becomes > "city_gate"="", "sport"="volleyball" becomes "volleyball"="", etc. And power=line becomes line="" and barrier=line becomes, uh, wait a minute. It is not so simple, even leaving aside the fact that many programs would simply dismiss your empty values. > Now, I don't actually think such an overhaul is currently feasible > given the massive burden it would put on the database system. > However, it might be something to think about for the future. I think that in theory what you call "super keys" is a good thing to have because it gives you a layered level of understanding. For example, if someone tags natural=water water=lake lake=turlough then you have a chance to understand "this is a natural feature" (and not man-made) even if you don't know what a lake is; you can understand "this is a lake" (and not a reservoir) even if you don't know what a turlough is; or you're so much into water bodies that you can actually understand the full message. If the tag was instead the space-saving turlough="" then you'd be stumped without recourse to the giant tag dictionary that explains to your renderer that something tagged turlough="" should perhaps be drawn in a blue-ish colour. Matter in a nutshell: Certainly the way we use these "super tags" has a lot of historical baggage but I don't think it is a stupid idea per se, *especially* if your goal is (like you're claiming yours to be) making tags easy for mappers. Bye Frederik -- Frederik Ramm ## eMail [email protected] ## N49°00'09" E008°23'33" _______________________________________________ Tagging mailing list [email protected] https://lists.openstreetmap.org/listinfo/tagging
