On 23 September 2012 15:21, Colin Smale <colin.sm...@xs4all.nl> wrote: > "CP" is part of the name in the OS Boundary-Line data. There doesn't seem to > be any consensus or guidelines about what to put in the "name" tag. Should > it be "Dartford" or "Dartford Borough" or "Borough of Dartford" or "Dartford > Council" or something else? Is it naming the area, or the administrative > entity governing it? As there are very many cases of areas at many levels > named identically, from counties down to parishes, there needs to be some > way of distinguishing between them. > > We have to watch out that we continue to distinguish distinct, unrelated > "hierarchies". In particular "parish" and "ward" mean different things > according to the context. There are civil parishes, which are (by > definition) a subarea of a higher-level local authority (normally > district/borough or unitary authority) and ecclesiastical parishes: each > religion/denomination has its own hierarchy of areas. The NHS has a > geographic hierarchy as has Fire and Rescue. But they have only a certain > correlation to governmental areas, with cases of one fire service serving > multiple counties, and a counties being covered by multiple fire services > (although I don't have an example of this to hand). > > An area at admin level 10 might be a civil parish, it might be an > ecclesiastical parish, it might be an electoral ward etc etc. To me, > boundary=administrative means the boundary belongs to "government", which > means it starts at level 2 with countries (leaving room for supra-national > levels such as the EU) and includes regions, counties, unitary authorities, > districts and civil parishes. Wards in this hierarchy should really be at > admin level 11 (i.e. inferior to parishes). There are some special cases > which don't fit the 100%: the Scilly Isles and City of London spring to > mind. There is a hierarchy of parliamentary-electoral areas as well; the > lowest quantum is the "ward" but these are not the same as the wards for > local council purposes.
Personally, and as the maintainer of nominatim I would be very happy to see admin_level dropped in favour of a set of specific tags (i.e. place=* or something similar). Admin_level is applied inconsistently and in ways that cause overlapping hierarchies. They also correlate badly between the place nodes and boundary relations - using a consistent set of tags across both would help no end in parsing the data! The current version of nominatim starts the process of linking admin boundaries to nodes - the next version will probably depreciate admin_level in favour of the place=* value from the label node where it is available. -- Brian _______________________________________________ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb
