[OSM-newbies] Polylines vs Polygons

[Craig Wallace]

On 06/12/2010 16:51, John-Michael Wiley wrote:
> What about feature types like natural or power which don’t seem to have a default type? For those should you always set the area='yes'.

This depends on the specific tag.
Check the Map Features page on the wiki, it specifies which tags can be 
used on ways, and which on areas. Look at the symbols in the column for 
"element": http://wiki.openstreetmap.org/wiki/Map_Features

eg natural=wood can only apply to nodes or areas, so any closed way is 
obviously an area, so no need to specify this.
Whereas natural=cliff can apply to nodes, ways or areas. So if mapping 
it as an area (with a closed way), its a good idea to specify area=yes. 
Or if you are mapping a circular cliff as a way, probably also helpful 
to set area=no on it.

Also for the power tags, things like power=line can only apply to ways. 
Whereas power=generator, power=substation can only apply to nodes and 
areas, so no need to set area=yes.


Craig