[Tagging] [Talk-us] shared driveways

[Anthony]

On Sat, Nov 21, 2009 at 4:01 PM, Frederik Ramm <frederik at remote.org> wrote:
> We tend to explicitly tag whether something belongs to the site or not.

That doesn't make it right.

> Anthony wrote:
>> It's redundant to have the same information
>> expressed twice, and doing so will only lead to conflicting data.
>
> The relation would express whether something is logically part of the
> site; the geometry would express whether something covers the same
> ground as the site. This is not the same information.

How not?  A bridge which goes over a site would be in a different
layer, and wouldn't "cover the same ground".  A road which goes
through the site, but is not considered part of the site, would split
the site into two parts, and would make the perimeter a multipolygon.

Note that all I said is "If you can outline a perimeter, you don't
need a relation."  If you can't outline a perimeter, then you may need
a relation.  Having a perimeter and a relation is the problem.