[Tagging] How to tag named group of named water areas?

Kevin Kenny kevin.b.kenny at gmail.com
Wed Nov 7 13:57:38 UTC 2018

On 11/7/18 2:27 AM, Dave Swarthout wrote:
> I provided two examples from the Wiki and a part of a response earlier 
> in this thread from Kevin Kenny to support my argument that state that 
> individual ways in a multipolygon or relation should not be tagged 
> unless their characteristics require it.  If you're working with a 
> route=road and the surface changes, you split the way and mark it so. 
> Same with maxspeed or number of lanes. The characteristics are those 
> of the way, not the entire route, and rightly belong only on the way.  
> In the case of the pipeline, tags like man_made=pipeline, 
> substance=oil, operator, Wikipedia and Wikidata tags, belong in the 
> relation. The people who first added the pipeline to OSM did it both 
> ways, probably to guarantee that it would be visible to OSM or other 
> data consumers, but I don't know.

That isn''t quite what I said.

What I said is that attributes that conceptually *might* be different on 
separate ways of a relation belong on the ways. What goes on the 
relation are the things that define it as a relation.

For a multipolygon, that's everything. A multipolygon is nothing more 
nor less than an area feature with any topology more complex than a 
simple closed way. The way gets tagging only if there's stuff that 
really belongs to it; an example would be an administrative region that 
ends at the coastline.

For a route, what goes on the relation is specifically the name of the 
route (if it has one that might be separate from the names of the 
constituent ways - for example, the Erie Canalway briefly follows State 
Street), the network, the reference number, and any descriptive 
information such as operator, website, length, hours, ... The physical 
attributes (highway=*, surface=*, etc.) go on the component ways.

For a group, it's even less. The Great Lakes relation has pretty much 
just a name and the component relations for the individual lakes.

Sorry if my earlier explanation was confusing.

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