I recently stumbled upon an import in the US prefixed with "dcgis". While this tagging makes it possible to have these data inserted parallely to other OSM data I still wonder why someone would do that.
In particular I am refering to this: http://taginfo.openstreetmap.org/keys/dcgis%3Aaddress I don't see the point why this is not the usual "addr:street" etc. and there seem to be also other issues: http://taginfo.openstreetmap.org/search?q=dcgis The most used tag in this "namespace" is "dcgis:captureyear" http://taginfo.openstreetmap.org/keys/dcgis%3Acaptureyear which can be found 93 022 times in the db but isn't documented in the wiki [1] Looking at the key name and values this looks like the date when the external database included the object in their system. Why on earth should we keep track of this in OSM? Doesn't seem to be a geoinformation to me. How should a mapper deal with these tags if he modifies an object? E.g. if there is a dcgis:acquired=6 ( http://taginfo.openstreetmap.org/keys/dcgis%3Aacquired ) on an object he splits? I suggest to modify [1] to not further encourage people to import all of the information from dcgis into osm, but only those that are useful. E.g. these sentences could be modified: "SSL and AID - The AID and SSL attributes are used to correlate the data with the DC MAR (Master Address Record) and should generally be preserved." "Pubdate - DC-GIS data includes a pubdate in the supplementary XML file. This should be included in the features as dcgis:pubdate and the date should be reformatted to YYYY-MM-DD" "Dataset - In order to preserve the origin of the data, the dataset should be specified. The naming of these datasets should map to the naming of the zipfile, ie PostOfficePt or ParkPly, the resulting key, value pair would be dc-gis:dataset=ParkPly" These are the keys named in the wiki, but the actual data contains much more keys, which aren't obvious in their meaning (at least to me), or which are almost pointless in a spatial database, or which would be much better suited for a changeset comment then for a tag on the object, e.g. dcgis:area dcgis:gis dcgis:length dcgis:list_info dcgis:nr_eligibl dcgis:update_date dcgis:url cheers, Martin [1] http://wiki.openstreetmap.org/wiki/Washington_DC/DCGIS_imports _______________________________________________ Tagging mailing list [email protected] http://lists.openstreetmap.org/listinfo/tagging
