Am 13.04.2012 08:20, schrieb Peter Wendorff: > If we would define a set of defaults and mappers follow that set, nobody > will add "default" values again, and it's not possible to distinguish > between default and unknown any more.
You have identified a real problem: The distinction between default and unknown values is lost with a default that is more than just a fallback for programs. And I agree that certain tags with more than one commonly used value should preferably be set explicitly everywhere. However, I think that relying on defaults cannot really be avoided in _all_ cases. For example, in many countries there are so few roads usable only with 4wd vehicles that you will never see the default explicitly tagged on all highways. Instead, you will have a small number of roads tagged as "4wd only", and a lot of roads for which we just assume not to have this restriction. So for attributes that almost always have a certain value, I really don't see any option except using that one as the default and accepting that this makes "undefined" essentially impossible. As a crude analogy: We don't add a node with "there's no shop here" at every unoccupied coordinate either. Instead, we just treat unmapped areas the same as areas where someone has already checked that there really is no shop around. There are just too many coordinates without shops, relatively speaking. And I think we will need to do the same for rare attributes, too. Tobias _______________________________________________ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging