[OSM-legal-talk] Attributions in WMS clients

Jukka Rahkonen jukka.rahkonen at mmmtike.fi
Sun Jan 11 13:43:44 UTC 2015

Wiktor Niesiobedzki <osm at ...> writes:

> Hi,
> We have in Poland some institutions that use WMS services, that use
> tiles generated from OSM. For example map available on:
> http://geoportal.nid.pl/nid/
> Has layers (warstwa in Polish) - Openstreetmap kolorowy and
> OpenStreetMap - monochromatyczny and use some external party
> (Terrestris) as a provider of this tiles using WMS.
> WMS address is:
> http://ows.terrestris.de/osm-gray/service
> And this WMS has attribution:
>  <AccessConstraints>(c) OpenStreetMap contributors
> (http://www.openstreetmap.org/copyright) (c) OpenStreetMap Data
> (http://openstreetmapdata.com) (c) Natural Earth Data
> (http://www.naturalearthdata.com)</AccessConstraints>
> On "electronic browsable map" - http://geoportal.nid.pl/nid/ ,
> attribution is only visible, if I choose from menu the information
> about OSM layer ("Dane pochodz─ů z projektu OpenStreetMap.")
> Though on our copyright page we require, that attribution is visible
> in the corner of the map. Is this required also for WMS clients, or as
> in such case - attribution on layer level is sufficient?
> I'm going to meet representative of this institution soon and as they
> were raised some issues about attribution which concerns them, I'd
> like to come back to them with definite answer if their attribution if
> sufficient. My fear is that WMS clients usually don't support showing
> attribution as we require right now.


My opinion is that if the link to OSM license in the access constraints
section of WMS GetCapabilities is correct then it is all that is needed on
the WMS service level. That's the way that WMS standard provides for
announcing the access constraints. It is a service level metadata element
and thus access constraints of OSM layers can't have a special treatment.
Therefore the list that is configured into the geoportal is ok.

It is usually possible to force WMS service to write a watermark into each
map which contains data from a certain layer but that is not required from
the tile services:


Tile providers have separate pages about usage policy: 


There is no fundamental difference between tile services and WMS and
therefore the AccessConstraints in WMS GetCapabilities and separate web page
in the Polish geoportal about how to attribute OSM in application should be
enough. It is up to the developers of web services which are based on WMS to
implement the OSM copyright into the corner of the map just like they must
to do that when they use tile services.

-Jukka Rahkonen-

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