[Tagging] layer=-1, rivers, bridges and tunnels

[Pieren]

On Fri, Mar 14, 2014 at 4:45 PM, Richard Z. <ricoz.osm at gmail.com> wrote:

> in theory yes. However "nearby" is a problem as rivers can be very long.
> Many people simply tag rivers with layer=-1 without even thinking about
> the fact that the rivers may now collide with tunnels some hundreds of miles
> away.

In general, we should avoid single ways running over hundreds of
miles. And we have QA tools to detect such issues.

> Furthermore there is a convention that if there is a crossing with a bridge,
> the bridge should have the layer tag and not the way bellow it. Similar tunnel.
> For both tunnels and bridges layer is now considered mandatory thus it is
> totally useless to put rivers at layer=-1 unless they are in a tunnel.

Who decided this and where ? The wiki about bridge says "Bridges
should have a layer=*, ". "should" is not "must".

Pieren