[Tagging] part_of:wikidata key

[Tod Fitch]

> On Nov 28, 2017, at 8:40 AM, Christoph Hormann <osm at imagico.de> wrote:
> 
> The problem is OSM is a map of the physical world, not a map of the 
> world's databases.  If Wikidata wants to create links between OSM and 
> other databases that is great but so far i think no one has made a good 
> case why this linking information should be stored in OSM rather than 
> Wikidata.
> 

Maybe because OSM does not have the concept of a permanent ID for feature in the real world so there is no way for other databases to maintain the linkage.