[Tagging] Basic philosophy of OSM tagging

[moltonel 3x Combo]

On 14/01/2015, Warin <61sundowner at gmail.com> wrote:
> Are 'we' tagging for
>
> What things are? eg highways
> OR
> What things are used for? eg amenity

Why does it have to be one exclusive_or the other ? Both what things
are and what they are used for is important. There's normally always a
way to tag both, even if the tags to do that can be a bit bysantine.
New tags may want to focus on one aspect or the other, there's no hard
rule.

The highway tag is a poor example for the nature/use dichotomy. The
interpretation differs by country (hopefully not within a country).
Some countries place more importance on use (amount and type of
traffic...) than on nature (surface, width...). Other countries adhere
rather strictly to the national road refs, even if the road changes
classification for purely administrative reasons (so neither nature
nor use). What the highway tag is a good example of, is the organic
evolution of osm's tagging system.

One good example of nature vs use is church buildings reconverted to
shops/pubs/tourist offices (all 3 can be seen in Dublin) and
place_of_worships in various incongruous buildings. The building tag
is now clearly documented as pertaining to the nature of things, but
this hasn't always been the case and a lot existing building tags have
dubious values.