[Tagging] Removal of "amenity" from OSM tagging

[Daniel Koć]

W dniu 15.05.2015 18:33, Martin Koppenhoefer napisał(a):

> the area tag is sort of a special tag, it is used as a geometry flag
> to say whether a closed way is linear or a polygon.

That is how we are used to think about it, but it's just a convention.

If you flip the point of view, you can say area is one of a most basic 
GIS objects and it means we have a filled polygon with some additional 
properties and functions probably (like name, school or highway), and 
one very special exception (value "no" is rare - 1,67%) telling it's a 
closed line (probably also with some properties).

It is strange, I agree, but still useful, coherent and no worse than 
building=no (0,01%, so also marginal, but useful and coherent too).

For many types of objects area=* is so basic, that we don't even use it 
explicitly unless we need to tell something is different this time. And 
it's also highly conventional, because no highway is a line in reality, 
it's always an area, but it just happened we started OSM with routing in 
mind (big and middle scale) rather than micromapping (micro scale) and 
to make things easier we assumed that closing the highway line by 
default means "area=no".

I think it was a clever move, sparing us additional typing and storage, 
but still in reality area is a basic concept with some exceptions, 
rather than special property of GIS objects.

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