[Tagging] Flat area in the mountains

[solitone]

Interesting contribution, Sebastian, thanks!

But... how did you find those two relations?

> I just looked in taginfo about natural=flat. This has someone used for
> very big areas in Slovakia
> (https://www.openstreetmap.org/relation/1934540,
> https://www.openstreetmap.org/relation/1934514).

In taginfo I see it’s used in 2 relations, but I can’t find them specifically.