[Tagging] change recommendation from "depth" to "length" for the adit length?

[Zecke]

Am 15.05.2017 um 16:04 schrieb Martin Koppenhoefer:
> how would you tag the adit then? (I'm asking for the feature that is 
> described in the wiki: a horizontal or almost horizontal tunnel going 
> into the underground)

I wouldn't map that at all. And if so, a tunnel=yes, layer=-1 should 
describe all that's necessary. I also see no reason to distinguish 
between an adit (as tunnel) and a drift when tagging. Where does the 
adit end and the drift begin? First crossing? So when really beginning 
to start a tagging scheme for underground mining facilities a would stay 
with the general terms drift or gallery for the ways, knowning that one 
could also name it an adit, if it has a surface end.

Carsten