[OSM-newbies] Interior ring with Potlatch?

[Randy]

Steve Bennett wrote:

>On Thu, Dec 10, 2009 at 4:45 PM, Randy 
><rwtnospam-newsgp at yahoo.com> wrote:
>>JOSM Validator has flagged one of those in my area. I think the tips of
>>the "C" may be overlapping a little, but I haven't gotten around to fixing
>>it yet. A multipolygon is, I believe, the best practice in this case,
>
>Undoubtedly.
>
>>since your "pseudo wall" isn't really an exterior part of the building.
>
>Oh, I didn't know they had to be. What do you do when there's a
>complex of clearly distinct buildings that touch each other? I thought
>tagging them separately (but sharing ways) was the right thing to
>do...
>
>Steve

Concede. "Exterior" was not a good word to use here, I was being lazy. How 
about "building boundary demarcation"? (Whether you agree with the intent 
of the statement or not.) Even though the building will be rendered as a 
whole (with a hole), the underlying data will indicate a discontinuity.

Regarding using a single way for multiple purposes, this is done quiet 
often, and I think very appropriate. However, I think the mapper should 
consider the potentially common boundary when doing this. Are either side 
of the boundary mutually exclusive? That's definitely a case for a common 
boundary. If the purposes of the potentially common way are unrelated, 
e.g. a highway and an area boundary, then is the area boundary likely to 
move if the highway moves? If yes, use a common boundary. If the two uses 
are not exclusive, and the relocation of one will not necessarily require 
the relocation of the other, then I think separate ways should be used. 
That will certainly ease the effort of the mapper who may eventually have 
to move one and not the other.

-- 
Randy